01st December 2022
In their new seminal study, researchers described a new functional principle that is important in the early phase of learning and that is present uniformly in the whole cerebral cortex. Using a previously unavailable tool and method the researchers recorded the activity of an important but scarcely present interneuron, the VIP-type (vasoactive intestinal polypeptide-expressing) interneuron. This inhibitory interneuron type represents barely 1% of the cortical cell population.
VIP neurons do inhibit other inhibitory interneurons that supress the activity of the pyramidal cells, thereby modulating the input gain on these neurones, that may provide a powerful tool in the learning process.
Due to the limitation of the methods available up to date (electrophysiology and imaging) our knowledge of this very important cell type is limited too. The reach of these methods misses the cell types that are rare in the cortex. The FEMTO3D Atlas microscope is able to record the chosen cells within a large cortical volume, even if they are sparse and have a small cell body. Recording speed, spatial resolution and signal-to-noise ratio of this special microscope far outperforms the imaging tools used so far.
The protocol of the experiments that was conducted by Zoltán Szadai, Hyun-Jae Pi and Quentin Chevy with the technical assistance of Lidia Popara consisted of controlled-water-access mice discriminating two tones. Successfully performing mice were rewarded with drops of water, whilst an error lead to an aversive air puff. To some surprise both the reward and the „punishment” lead to a strong, phasic activation of the VIP cells, and all over the cortex. This outcome shows that VIP interneurons actually relay information locally about an organism-level information on reinforcers, helping regulate local processing and leading to plasticity.
The study thus represents a step closer to understanding a cortex-wide mechanism of perception and learning, therefore provides basis for further investigations of healthy and pathological changes. The study also provides evidence for a similarity of reinforcement learning in organic brains and artificial intelligence models.
Congratulations to the authors for their discovery!
Read the whole article here.
[content] => [custom_date] => 01st December 2022 ) -------------------------Array ( [title] => Array ( [0] => Cortex-wide response mode of VIP-expressing inhibitory neurons by reward and punishment ) [_title] => Array ( [0] => field_5d569e14e7fac ) [post_or_link] => Array ( [0] => post ) [_post_or_link] => Array ( [0] => field_5d721a6b01771 ) [author] => Array ( [0] => Zoltán Szadai, Hyun-Jae Pi, Quentin Chevy, Katalin Ócsai, Dinu F Albeanu, Balázs Chiovini, Gergely Szalay, Gergely Katona, Adam Kepecs ) [_author] => Array ( [0] => field_5d6e07fd03a47 ) [author_short2] => Array ( [0] => ) [_author_short2] => Array ( [0] => field_5ecfaf6469bfc ) [mini_image] => Array ( [0] => 10629 ) [_mini_image] => Array ( [0] => field_5d569e24259e3 ) [image] => Array ( [0] => 10697 ) [_image] => Array ( [0] => field_5d569e14e8391 ) [article_first_paragraphs] => Array ( [0] =>In their new seminal study, researchers described a new functional principle that is important in the early phase of learning and that is present uniformly in the whole cerebral cortex. Using a previously unavailable tool and method the researchers recorded the activity of an important but scarcely present interneuron, the VIP-type (vasoactive intestinal polypeptide-expressing) interneuron. This inhibitory interneuron type represents barely 1% of the cortical cell population.
VIP neurons do inhibit other inhibitory interneurons that supress the activity of the pyramidal cells, thereby modulating the input gain on these neurones, that may provide a powerful tool in the learning process.
Due to the limitation of the methods available up to date (electrophysiology and imaging) our knowledge of this very important cell type is limited too. The reach of these methods misses the cell types that are rare in the cortex. The FEMTO3D Atlas microscope is able to record the chosen cells within a large cortical volume, even if they are sparse and have a small cell body. Recording speed, spatial resolution and signal-to-noise ratio of this special microscope far outperforms the imaging tools used so far.
The protocol of the experiments that was conducted by Zoltán Szadai, Hyun-Jae Pi and Quentin Chevy with the technical assistance of Lidia Popara consisted of controlled-water-access mice discriminating two tones. Successfully performing mice were rewarded with drops of water, whilst an error lead to an aversive air puff. To some surprise both the reward and the „punishment” lead to a strong, phasic activation of the VIP cells, and all over the cortex. This outcome shows that VIP interneurons actually relay information locally about an organism-level information on reinforcers, helping regulate local processing and leading to plasticity.
The study thus represents a step closer to understanding a cortex-wide mechanism of perception and learning, therefore provides basis for further investigations of healthy and pathological changes. The study also provides evidence for a similarity of reinforcement learning in organic brains and artificial intelligence models.
Congratulations to the authors for their discovery!
Read the whole article here.
) [_article_first_paragraphs] => Array ( [0] => field_5d569e61259e4 ) [content] => Array ( [0] => ) [_content] => Array ( [0] => field_5d569e14e8782 ) [custom_date] => Array ( [0] => 2022-12-01 00:00:00 ) [_custom_date] => Array ( [0] => field_5d569e14e8b57 ) [_yoast_wpseo_estimated-reading-time-minutes] => Array ( [0] => ) [_wp_old_date] => Array ( [0] => 2022-11-14 ) [_dp_original] => Array ( [0] => 10433 ) [_edit_lock] => Array ( [0] => 1681892993:11 ) [_edit_last] => Array ( [0] => 7 ) [_wp_old_slug] => Array ( [0] => cortex-wide-response-mode-of-vip-expressing-inhibitory-neurons ) ) -----------------------------------------------------07th November 2022
A recent Nature Communications study utilized cutting-edge techniques to gain new insights into neuronal plasticity. Researchers at IEM ELRN and BVC (BrainVisionCenter Knowledge and Competence Center, founded in 2021 by Botond Roska, Balázs Rózsa, and ITM), in cooperation with PPCU and FMI Basel, studied events called sharp-wave ripples (SPW-Rs) on the cellular processes in the hippocampus during behavior, in the framework of their first, ambitious collaboration.
SPW-Rs play a crucial role in memory consolidation, encoding, and retrieval. It has been suggested that SPW-R-associated cell assemblies induce spatiotemporally clustered activity known as dendritic „hot-spots” in the dendrites of hippocampal PV+ interneurons. However, technical limitations have yet prevented researchers from demonstrating in vivo SPW-R-associated regenerative dendritic processes.
Linda Judák, Balázs Chiovini, Balázs Rózsa (head of the Laboratory of 3D functional network and dendritic imaging, IEM ELRN) and colleagues combined ultra-fast 3D acousto-optic (AO) imaging with the viral vector labeling method of Botond Roska and ipsilateral local field potential recording to map the dendritic activity across entire dendritic arbors of PV+ cells in vivo. 3D AO imaging gave them fast access to long, thin dendritic segments simultaneously in multiple locations along the entire 3D dendritic arbor (with a total length of over 1500 μm) of PV+ cells of awake, behaving animals, with fast motion-artifact elimination at high resolution. The AO-based FEMTO3D Atlas allowed the group to demonstrate local dendritic spikes (dSpikes) in PV+ cells for the first time, in a large 3D volume in real time. Their results show how dSpikes can function as a dendritic-level temporal and spatial coincidence detector during network computation.
Read the whole article here.
[content] => [custom_date] => 07th November 2022 ) -------------------------Array ( [title] => Array ( [0] => Sharp-wave ripple doublets induce complex dendritic spikes in parvalbumin interneurons in vivo ) [_title] => Array ( [0] => field_5d569e14e7fac ) [post_or_link] => Array ( [0] => post ) [_post_or_link] => Array ( [0] => field_5d721a6b01771 ) [author] => Array ( [0] => Linda Judák, Balázs Chiovini, Gábor Juhász, Dénes Pálfi, Zsolt Mezriczky, Zoltán Szadai, Gergely Katona, Benedek Szmola, Katalin Ócsai, Bernadett Martinecz, Anna Mihály, Ádám Dénes, Bálint Kerekes, Áron Szepesi, Gergely Szalay, István Ulbert, Zoltán Mucsi, Botond Roska & Balázs Rózsa ) [_author] => Array ( [0] => field_5d6e07fd03a47 ) [author_short2] => Array ( [0] => ) [_author_short2] => Array ( [0] => field_5ecfaf6469bfc ) [mini_image] => Array ( [0] => 10418 ) [_mini_image] => Array ( [0] => field_5d569e24259e3 ) [image] => Array ( [0] => 10698 ) [_image] => Array ( [0] => field_5d569e14e8391 ) [article_first_paragraphs] => Array ( [0] =>A recent Nature Communications study utilized cutting-edge techniques to gain new insights into neuronal plasticity. Researchers at IEM ELRN and BVC (BrainVisionCenter Knowledge and Competence Center, founded in 2021 by Botond Roska, Balázs Rózsa, and ITM), in cooperation with PPCU and FMI Basel, studied events called sharp-wave ripples (SPW-Rs) on the cellular processes in the hippocampus during behavior, in the framework of their first, ambitious collaboration.
SPW-Rs play a crucial role in memory consolidation, encoding, and retrieval. It has been suggested that SPW-R-associated cell assemblies induce spatiotemporally clustered activity known as dendritic „hot-spots” in the dendrites of hippocampal PV+ interneurons. However, technical limitations have yet prevented researchers from demonstrating in vivo SPW-R-associated regenerative dendritic processes.
Linda Judák, Balázs Chiovini, Balázs Rózsa (head of the Laboratory of 3D functional network and dendritic imaging, IEM ELRN) and colleagues combined ultra-fast 3D acousto-optic (AO) imaging with the viral vector labeling method of Botond Roska and ipsilateral local field potential recording to map the dendritic activity across entire dendritic arbors of PV+ cells in vivo. 3D AO imaging gave them fast access to long, thin dendritic segments simultaneously in multiple locations along the entire 3D dendritic arbor (with a total length of over 1500 μm) of PV+ cells of awake, behaving animals, with fast motion-artifact elimination at high resolution. The AO-based FEMTO3D Atlas allowed the group to demonstrate local dendritic spikes (dSpikes) in PV+ cells for the first time, in a large 3D volume in real time. Their results show how dSpikes can function as a dendritic-level temporal and spatial coincidence detector during network computation.
Read the whole article here.
) [_article_first_paragraphs] => Array ( [0] => field_5d569e61259e4 ) [content] => Array ( [0] => ) [_content] => Array ( [0] => field_5d569e14e8782 ) [custom_date] => Array ( [0] => 2022-11-07 00:00:00 ) [_custom_date] => Array ( [0] => field_5d569e14e8b57 ) [_yoast_wpseo_estimated-reading-time-minutes] => Array ( [0] => ) [_dp_original] => Array ( [0] => 10417 ) [_edit_lock] => Array ( [0] => 1672908123:7 ) [_wp_old_date] => Array ( [0] => 2022-11-14 ) [_edit_last] => Array ( [0] => 7 ) ) -----------------------------------------------------24th February 2022
Microglia, the main immunocompetent cells of the brain, regulate neuronal function, but their contribution to cerebral blood flow (CBF) regulation has remained elusive. In an excellent 2022 paper published in the Journal of Experimental Medicine by Császár et al. from the laboratory of Ádám Dénes, PhD (IEM ELRN) microglia have been identified as important modulators of CBF both under physiological conditions and during hypoperfusion. They have shown that microglia establish direct, dynamic purinergic contacts with cells in the neurovascular unit that shape CBF. The group has investigated the formation and dynamics of microglia–vascular interactions using in vivo two-photon imaging performed on a dual scanhead FEMTOSmart Dual two-photon laser scanning system.
In conclusion, the authors demonstrate that microglia should be considered an important modulatory cell type involved in physiological and pathological alterations of CBF. Understanding their actions may facilitate the discovery of novel treatment opportunities for common neurological disorders.
Read the full article here.
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In conclusion, the authors demonstrate that microglia should be considered an important modulatory cell type involved in physiological and pathological alterations of CBF. Understanding their actions may facilitate the discovery of novel treatment opportunities for common neurological disorders.
Read the full article here.
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A recently published breakthrough Nature paper upends decades of dogma about memory storage and formation in the hippocampus.
Place cells, the pyramidal neurons responsible for constructing and maintaining cognitive maps, create sparse networks in the hippocampus. As scientists usually investigate the activity of either single neurons, or brain regions consisting of large amounts of cells, much remains unknown about small circuits of place cells linked together in intimate conversation. For the first time, Geiller et al. from the team of Attila Losonczy (Professor of Neuroscience at Columbia University) have developed a method to not only detect the activity of individual hippocampal place cells forming spatial maps in real time, but also that of all the neurons connected to them: including excitatory neurons and inhibitory interneurons.
This exceptional feat would not have been possible without combining cutting-edge techniques and lab tools, one of which is the FEMTO3D Atlas acousto-optic two-photon microscope, which can target and follow 3D networks of sparsely distributed neurons even in deep brain regions simultaneously, with high SNR. With this tool in hand, the team has made the dogma-defying discovery that neurons in the memory center of the brain are much more connected than previously thought. They learn collaboratively in local groups, storing information redundantly – similarly to holograms. Ultimately, a better understanding of the fundamentals of how memories are formed can lead to better treatments for conditions associated with memory problems.
Read the whole article here.
[content] => [custom_date] => 01st December 2021 ) -------------------------Array ( [_edit_lock] => Array ( [0] => 1668180028:8 ) [_edit_last] => Array ( [0] => 8 ) [title] => Array ( [0] => Local circuit amplification of spatial selectivity in the hippocampus ) [_title] => Array ( [0] => field_5d569e14e7fac ) [post_or_link] => Array ( [0] => post ) [_post_or_link] => Array ( [0] => field_5d721a6b01771 ) [author] => Array ( [0] => Tristan Geiller, Sadra Sadeh, Sebastian V. Rolotti, Heike Blockus, Bert Vancura, Adrian Negrean, Andrew J. Murray, Balázs Rózsa, Franck Polleux, Claudia Clopath & Attila Losonczy ) [_author] => Array ( [0] => field_5d6e07fd03a47 ) [author_short2] => Array ( [0] => ) [_author_short2] => Array ( [0] => field_5ecfaf6469bfc ) [mini_image] => Array ( [0] => 2615 ) [_mini_image] => Array ( [0] => field_5d569e24259e3 ) [image] => Array ( [0] => 8047 ) [_image] => Array ( [0] => field_5d569e14e8391 ) [article_first_paragraphs] => Array ( [0] =>A recently published breakthrough Nature paper upends decades of dogma about memory storage and formation in the hippocampus.
Place cells, the pyramidal neurons responsible for constructing and maintaining cognitive maps, create sparse networks in the hippocampus. As scientists usually investigate the activity of either single neurons, or brain regions consisting of large amounts of cells, much remains unknown about small circuits of place cells linked together in intimate conversation. For the first time, Geiller et al. from the team of Attila Losonczy (Professor of Neuroscience at Columbia University) have developed a method to not only detect the activity of individual hippocampal place cells forming spatial maps in real time, but also that of all the neurons connected to them: including excitatory neurons and inhibitory interneurons.
This exceptional feat would not have been possible without combining cutting-edge techniques and lab tools, one of which is the FEMTO3D Atlas acousto-optic two-photon microscope, which can target and follow 3D networks of sparsely distributed neurons even in deep brain regions simultaneously, with high SNR. With this tool in hand, the team has made the dogma-defying discovery that neurons in the memory center of the brain are much more connected than previously thought. They learn collaboratively in local groups, storing information redundantly - similarly to holograms. Ultimately, a better understanding of the fundamentals of how memories are formed can lead to better treatments for conditions associated with memory problems.
Read the whole article here.
) [_article_first_paragraphs] => Array ( [0] => field_5d569e61259e4 ) [content] => Array ( [0] => ) [_content] => Array ( [0] => field_5d569e14e8782 ) [custom_date] => Array ( [0] => 2021-12-01 00:00:00 ) [_custom_date] => Array ( [0] => field_5d569e14e8b57 ) [_yoast_wpseo_estimated-reading-time-minutes] => Array ( [0] => ) ) -----------------------------------------------------03rd June 2021
B. Chiovini, D. Pálfi, M. Majoros, G. Juhász, G. Szalay, G. Katona, M. Szőri, O. Frigyesi, Cs. Lukácsné Haveland, G. Szabó, F. Erdélyi, Z. Máté, Z. Szadai, M. Madarász, M. Dékány, I. G. Csizmadia, E. Kovács, B. Rózsa, and Z. Mucsi
07th May 2021
A. Kaszas, G. Szalay, A. Slézia, A. Bojdán, I. Vanzetta, B. Hangya, B. Rózsa, R. O’Connor & D. Moreau
05th October 2020
T. Geiller, B. Vancura, S. Terada, E. Troullinou, S. Chavlis, G. Tsagkatakis, P. Tsakalides, K. Ócsai, P. Poirazi, B. J. Rózsa, A. Losonczy
05th October 2020
C. S. Cowan, M. Renner, M. De Gennaro, B. Gross-Scherf, D.Goldblum, Y. Hou, M. Munz, T. M. Rodrigues, J. Krol, T. Szikra, R. Cuttat, A. Waldt, P. Papasaikas, R. Diggelmann, C. P. Patino-Alvarez, P. Galliker, S. E. Spirig, D. Pavlinic, N. Gerber-Hollbach, S. Schuierer, A. Srdanovic, M. Balogh, R. Panero, A. Kusnyerik, A. Szabo, M. B. Stadler, S. Orgül, S. Picelli, P. W. Hasler, A. Hierlemann, H. P. N. Scholl, G. Roma, F. Nigsch, B. Roska
05th June 2020
D. Nelidova, R. K. Morikawa, C. S. Cowan, Z. Raics, D. Goldblum, H. P. N. Scholl, T. Szikra, A. Szabo, D. Hillier, B. Roska
03rd January 2020
A. Gidon, T. A. Zolnik, P. Fidzinski, F. Bolduan, A. Papoutsi, P. Poirazi, M. Holtkamp, I. Vida, M. E. Larkum
27th December 2019
V. Francioni, Z. Padamsey, N. L Rochefort
31st January 2020
Cs. Cserép, B. Pósfai, N. Lénárt, R. Fekete, Zs. I. László, Zs. Lele, B. Orsolits, G. Molnár, S. Heindl, A. D. Schwarcz, K. Ujvári, Zs. Környei, K. Tóth, E. Szabadits, B. Sperlágh, M. Baranyi, L. Csiba, T. Hortobágyi, Zs. Maglóczky, B. Martinecz, G. Szabó, F. Erdélyi, R. Szipőcs, M. M. Tamkun, B. Gesierich, M. Duering, I. Katona, A. Liesz, G. Tamás, Á. Dénes
03rd May 2016
G. Szalay, B. Martinecz, N. Lénárt, Zs. Környei, B. Orsolits, L. Judák, E. Császár, R. Fekete, B. L. West, G. Katona, B. Rózsa & Á. Dénes
01st August 2016
G. Szalay, L. Judak, G. Katona, K. Ocsai, G. Juhasz, M. Veress, Z. Szadai, A. Feher, T. Tompa, B. Chiovini, P. Maak, B. Rozsa
05th October 2015
M. A. Popovic, N. Carnevale, B. Rozsa & D. Zecevic
21st October 2015
Zheng et al demonstrated in Neuron, that mapped basal Ca2+ in neurons and astrocytes with submicron resolution helps to unveil heterogeneous concentration landscapes that depend on age and preceding activity of the bain. Monitoring nanomolar-scale molecular interaction between OGB1 nanomolar sensitivity dye and Ca2+ was performed by Femto2D-Galvo equipped with FLIM module. The new generation of Femto2D-Galvo is the FEMTOSmart Galvo: read more about its technical features and benefits.
[content] => [custom_date] => 21st October 2015 ) -------------------------Array ( [_edit_lock] => Array ( [0] => 1613167450:6 ) [_edit_last] => Array ( [0] => 6 ) [title] => Array ( [0] => Time-Resolved Imaging Reveals Heterogeneous Landscapes of Nanomolar Ca2+ in Neurons and Astroglia ) [_title] => Array ( [0] => field_5d569e14e7fac ) [post_or_link] => Array ( [0] => post ) [_post_or_link] => Array ( [0] => field_5d721a6b01771 ) [author] => Array ( [0] => Kaiyu Zheng, Lucie Bard, James P. Reynolds, Claire King, Thomas P. Jensen, Alexander V. Gourine, Dmitri A. Rusakov ) [_author] => Array ( [0] => field_5d6e07fd03a47 ) [mini_image] => Array ( [0] => 1318 ) [_mini_image] => Array ( [0] => field_5d569e24259e3 ) [image] => Array ( [0] => 2424 ) [_image] => Array ( [0] => field_5d569e14e8391 ) [article_first_paragraphs] => Array ( [0] =>Zheng et al demonstrated in Neuron, that mapped basal Ca2+ in neurons and astrocytes with submicron resolution helps to unveil heterogeneous concentration landscapes that depend on age and preceding activity of the bain. Monitoring nanomolar-scale molecular interaction between OGB1 nanomolar sensitivity dye and Ca2+ was performed by Femto2D-Galvo equipped with FLIM module. The new generation of Femto2D-Galvo is the FEMTOSmart Galvo: read more about its technical features and benefits.
) [_article_first_paragraphs] => Array ( [0] => field_5d569e61259e4 ) [content] => Array ( [0] => ) [_content] => Array ( [0] => field_5d569e14e8782 ) [custom_date] => Array ( [0] => 2015-10-21 00:00:00 ) [_custom_date] => Array ( [0] => field_5d569e14e8b57 ) [_yoast_wpseo_content_score] => Array ( [0] => 30 ) [author_short] => Array ( [0] => ) [_author_short] => Array ( [0] => field_5ec4e81c596dc ) ) -----------------------------------------------------03rd July 2015
Roska’s lab (FMI, Basel) mapped the presynaptic network of a V1 orientation selective neuron by using a single-cell-initiated, monosynaptically restricted, retrograde transsynaptic network tracing with rabies viruses. The labeled neurons expressed GCaMP6s, which allowed to image, in vivo, the visual motion-evoked activity of individual layer 2/3 pyramidal neurons and their whole presynaptic networks across layers in the primary visual cortex of the mice. For the measurement of this large number of neurons scattered across the width of the cortex they used a Femto3D-AO microscope. They found that the neurons within each layer exhibited similar motion direction preferences, forming layer-specific functional modules. In one third of the networks, the layer modules were locked to the direction preference of the postsynaptic neuron, whereas for other networks the direction preference varied by layer. The new generation of Femto3D-AcoustoOpctic microscope is the FEMTO3D Atlas: read more about its technical features and benefits.
[content] => [custom_date] => 03rd July 2015 ) -------------------------Array ( [_edit_lock] => Array ( [0] => 1591097815:6 ) [_edit_last] => Array ( [0] => 6 ) [title] => Array ( [0] => Single-cell–initiated monosynaptic tracing reveals layer-specific cortical network modules ) [_title] => Array ( [0] => field_5d569e14e7fac ) [post_or_link] => Array ( [0] => post ) [_post_or_link] => Array ( [0] => field_5d721a6b01771 ) [author] => Array ( [0] => Wertz A, Trenholm S, Yonehara K, Hillier D, Raics Z, Leinweber M, Szalay G, Ghanem A, Keller G, Rozsa B, Conzelmann KK, Roska B ) [_author] => Array ( [0] => field_5d6e07fd03a47 ) [mini_image] => Array ( [0] => 2439 ) [_mini_image] => Array ( [0] => field_5d569e24259e3 ) [image] => Array ( [0] => 2438 ) [_image] => Array ( [0] => field_5d569e14e8391 ) [article_first_paragraphs] => Array ( [0] =>Roska’s lab (FMI, Basel) mapped the presynaptic network of a V1 orientation selective neuron by using a single-cell-initiated, monosynaptically restricted, retrograde transsynaptic network tracing with rabies viruses. The labeled neurons expressed GCaMP6s, which allowed to image, in vivo, the visual motion-evoked activity of individual layer 2/3 pyramidal neurons and their whole presynaptic networks across layers in the primary visual cortex of the mice. For the measurement of this large number of neurons scattered across the width of the cortex they used a Femto3D-AO microscope. They found that the neurons within each layer exhibited similar motion direction preferences, forming layer-specific functional modules. In one third of the networks, the layer modules were locked to the direction preference of the postsynaptic neuron, whereas for other networks the direction preference varied by layer. The new generation of Femto3D-AcoustoOpctic microscope is the FEMTO3D Atlas: read more about its technical features and benefits.
) [_article_first_paragraphs] => Array ( [0] => field_5d569e61259e4 ) [content] => Array ( [0] => ) [_content] => Array ( [0] => field_5d569e14e8782 ) [custom_date] => Array ( [0] => 2015-07-03 00:00:00 ) [_custom_date] => Array ( [0] => field_5d569e14e8b57 ) [_yoast_wpseo_content_score] => Array ( [0] => 30 ) [author_short] => Array ( [0] => ) [_author_short] => Array ( [0] => field_5ec4e81c596dc ) ) -----------------------------------------------------11th September 2014
B. P. Kerekes, K. Toth, A. Kaszas, B. Chiovini, Z. Szadai, G. Szalay, D. Palfi, A. Bago, K. Spitzer, B. Rozsa, I. Ulbert, L. Wittner
21st May 2014
Using fast 3D two-photon imaging (Femto3D-AO) in combination with electrophysiological recordings and a caged glutamate compound (DNI-Glu-TFA), Chiovini et al demonstrated that a single activation of clustered glutamatergic inputs in the distal dendrites of FS-PV INs, which generate a depolarizing hump and reproduce the hot spots associated with spontaneous SPW-R events, is capable of generating secondary membrane oscillations in the ripple frequency range. The new generation of Femto3D-AO microscope is the FEMTO3D Atlas: read more about its technical features and benefits.
[content] => [custom_date] => 21st May 2014 ) -------------------------Array ( [_edit_lock] => Array ( [0] => 1591097734:6 ) [_edit_last] => Array ( [0] => 6 ) [title] => Array ( [0] => Dendritic Spikes Induce Ripples in Parvalbumin Interneurons during Hippocampal Sharp Waves ) [_title] => Array ( [0] => field_5d569e14e7fac ) [post_or_link] => Array ( [0] => post ) [_post_or_link] => Array ( [0] => field_5d721a6b01771 ) [author] => Array ( [0] => B. Chiovini, G. F. Turi, G. Katona, A. Kaszas, D. Palfi, P. Maak, G. Szalay, M. F. Szabo, Z. Szadai, Sz. Kali and B. Rozsa ) [_author] => Array ( [0] => field_5d6e07fd03a47 ) [mini_image] => Array ( [0] => 1318 ) [_mini_image] => Array ( [0] => field_5d569e24259e3 ) [image] => Array ( [0] => 2442 ) [_image] => Array ( [0] => field_5d569e14e8391 ) [article_first_paragraphs] => Array ( [0] =>Using fast 3D two-photon imaging (Femto3D-AO) in combination with electrophysiological recordings and a caged glutamate compound (DNI-Glu-TFA), Chiovini et al demonstrated that a single activation of clustered glutamatergic inputs in the distal dendrites of FS-PV INs, which generate a depolarizing hump and reproduce the hot spots associated with spontaneous SPW-R events, is capable of generating secondary membrane oscillations in the ripple frequency range. The new generation of Femto3D-AO microscope is the FEMTO3D Atlas: read more about its technical features and benefits.
) [_article_first_paragraphs] => Array ( [0] => field_5d569e61259e4 ) [content] => Array ( [0] => ) [_content] => Array ( [0] => field_5d569e14e8782 ) [custom_date] => Array ( [0] => 2014-05-21 00:00:00 ) [_custom_date] => Array ( [0] => field_5d569e14e8b57 ) [_yoast_wpseo_content_score] => Array ( [0] => 30 ) [author_short] => Array ( [0] => ) [_author_short] => Array ( [0] => field_5ec4e81c596dc ) ) -----------------------------------------------------08th January 2012
G. Katona, G. Szalay, P. Maák, A. Kaszás, M. Veress, D. Hillier, B. Chiovini, E. S. Vizi, B. Roska & B. Rózsa
Kaiyu Zheng, Lucie Bard, James P. Reynolds, Claire King, Thomas P. Jensen, Alexander V. Gourine, Dmitri A. Rusakov
21st October 2015
Zheng et al demonstrated in Neuron, that mapped basal Ca2+ in neurons and astrocytes with submicron resolution helps to unveil heterogeneous concentration landscapes that depend on age and preceding activity of the bain. Monitoring nanomolar-scale molecular interaction between OGB1 nanomolar sensitivity dye and Ca2+ was performed by Femto2D-Galvo equipped with FLIM module. The new generation of Femto2D-Galvo is the FEMTOSmart Galvo: read more about its technical features and benefits.
2023
Pyramidal neurons form active, transient, multilayered circuits perturbed by autism-associated mutations at the inception of neocortex
Volume-transmitted GABA waves pace epileptiform rhythms in the hippocampal network
Organization and Plasticity of Inhibition in Hippocampal Recurrent Circuits
Spectrally Focused Stimulated Raman Scattering (sf-SRS) Microscopy for Label-Free Investigations of Molecular Mechanisms in Living Organisms
Delaying the GABA shift indirectly affects membrane properties in the developing hippocampus
Astrocytic Kir4.1 channels regulate locomotion by orchestrating neuronal rhythmicity in the spinal network
Impaired dynamics of precapillary sphincters and pericytes at first-order capillaries predict reduced neurovascular function in the aging mouse brain
Parvalbumin basket cell myelination accumulates axonal mitochondria to internodes
Macaque V1 responses to 2nd-order contrast-modulated stimuli and the possible subcortical and cortical contributions
Characterization of Electrospun Polysuccinimide-dopamine Conjugates and Effect on Cell Viability and Uptake
2022
Cortex-wide response mode of VIP-expressing inhibitory neurons by reward and punishment
Brivaracetam Modulates Short-Term Synaptic Activity and Low-Frequency Spontaneous Brain Activity by Delaying Synaptic Vesicle Recycling in Two Distinct Rodent Models of Epileptic Seizures.
Seeing beyond the spikes: reconstructing the complete spatiotemporal membrane potential distribution from paired intra-and extracellular recordings
Using SuperClomeleon to Measure Changes in Intracellular Chloride during Development and after Early Life Stress
Sharp-wave ripple doublets induce complex dendritic spikes in parvalbumin interneurons in vivo
A recent Nature Communications study has utilized cutting-edge techniques to gain new insights into neuronal plasticity.
The group of Balázs Rózsa MD, PhD (head of laboratories at IEM ELRN and PPCU), also affiliated with FMI and IOB, Basel and BVC, have studied events called sharp-wave ripples (SPW-Rs) on the cellular processes in the hippocampus during behavior. SPW-Rs, the most synchronous oscillations in the nervous system, play a crucial role in memory consolidation, encoding, and retrieval. It has been suggested that SPW-R-associated cell assemblies provide synchronized inputs to the dendrites of hippocampal PV+ interneurons. However, technical limitations have prevented researchers from mapping the dendritic activity across entire dendritic arbors of PV+ cells in vivo.
Here, the authors utilized ultra-fast 3D acousto-optic (AO) imaging through a deep brain adapter and ipsilateral local field potential recordings to do just that. This technique gave them fast access to long, thin dendritic segments simultaneously in multiple locations along the entire dendritic arbor (with a total length of over 1500 μm) of PV+ cells in 3D in vivo, at an orders-of-magnitude higher speed and SNR than previous imaging methods. The AO-based FEMTO3D Atlas has allowed the group to demonstrate local dendritic spikes (dSpikes) in PV+ cells, in a large 3D volume in real time, and to show how they are generated and travel on these processes, contributing to events leading to memory formation. Their results show how dSpikes can function as a dendritic-level temporal and spatial coincidence detector during network computation.
Read the whole article here.
[content] => [custom_date] => 07th November 2022 [link_to_publication] => https://www.nature.com/articles/s41467-022-34520-1 ) Macaque V1 responses to 2nd-order contrast-modulated stimuli and the possible subcortical and cortical contributions
Monitoring cell membrane recycling dynamics of proteins using whole-cell fluorescence recovery after photobleaching of pH-sensitive genetic tags
Fabrication and in vivo 2-photon microscopy validation of transparent PEDOT:PSS microelectrode arrays
Transparent Thiol-ene/Acrylate-Based MicroECoG Devices Used for Concurrent Recording of Fluorescent Calcium Signals and Electrophysiology in Awake Animals
Visual recognition of social signals by a tectothalamic neural circuit
Olfactory modulation of barrel cortex activity during active whisking and passive whisker stimulation
Characterization and ex vivo evaluation of excised skin samples as substitutes for human dermal barrier in pharmaceutical and dermatological studies
All-viral tracing of monosynaptic inputs to single birthdate-defined neurons in the intact brain
Non-uniform distribution of dendritic nonlinearities differentially engages thalamostriatal and corticostriatal inputs onto cholinergic interneurons
Ultrasound induced, easy-to-store porous poly(amino acid) based electrospun scaffolds
General anesthesia globally synchronizes activity selectively in layer 5 cortical pyramidal neurons
Dynamic interplay between thalamic activity and Cajal-Retzius cells regulates the wiring of cortical layer 1
Drug Delivery through the Psoriatic Epidermal Barrier—A “Skin-On-A-Chip” Permeability Study and Ex Vivo Optical Imaging
Microglia modulate blood flow, neurovascular coupling, and hypoperfusion via purinergic actions
The Cl- channel TMEM16A is involved in the generation of cochlear Ca2+ waves and promotes the refinement of auditory brainstem networks in mice
K+ efflux through postsynaptic NMDA receptors suppresses local astrocytic glutamate uptake
The NKCC1 ion transporter modulates microglial phenotype and inflammatory response to brain injury in a cell-autonomous manner
2021
Astroglial ER-mitochondria calcium transfer mediates endocannabinoid-dependent synaptic integration
Local circuit amplification of spatial selectivity in the hippocampus
Culturing and Scaling up Stem Cells of Dental Pulp Origin Using Microcarriers
Synthesis and Fluorescence Mechanism of the Aminoimidazolone Analogues of the Green Fluorescent Protein: Towards Advanced Dyes with Enhanced Stokes Shift, Quantum Yield and Two-Photon Absorption
Calcium dependence of neurotransmitter release at a high fidelity synapse
Axonal CB1 receptors mediate inhibitory bouton formation via cAMP increase and PKA
Integrating flexible electronics for pulsed electric field delivery in a vascularized 3D glioblastoma model
Poly(amino acid) based fibrous membranes with tuneable in vivo biodegradation
Dendritic Kv4.2 potassium channels selectively mediate spatial pattern separation in the dentate gyrus
Visual stimulation with blue wavelength light drives V1 effectively eliminating stray light contamination during two-photon calcium imaging
Recruitment of release sites underlies chemical presynaptic potentiation at hippocampal mossy fiber boutons
Theoretical Design, Synthesis, and In Vitro Neurobiological Applications of a Highly Efficient Two-Photon Caged GABA Validated on an Epileptic Case
Top-down acetylcholine signaling via olfactory bulb vasopressin cells contributes to social discrimination in rats
Two-photon GCaMP6f imaging of infrared neural stimulation evoked calcium signals in mouse cortical neurons in vivo
Astrocyte Ca2+ Waves and Subsequent Non-Synchronized Ca2+ Oscillations Coincide with Arteriole Diameter Changes in Response to Spreading Depolarization
Subcellular Dissection of a Simple Neural Circuit: Functional Domains of the Mauthner-Cell During Habituation
Automatic deep learning-driven label-free image-guided patch clamp system
Release probability increases towards distal dendrites boosting high-frequency signal transfer in the rodent hippocampus
Large, Stable Spikes Exhibit Differential Broadening in Excitatory and Inhibitory Neocortical Boutons
2020
Molecular classification of zebrafish retinal ganglion cells links genes to cell types to behavior
Neural circuitry for stimulus selection in the zebrafish visual system
Optimization aspects of electrodeposition of photoluminescent conductive polymer layer onto neural microelectrode arrays
Functional, molecular and morphological heterogeneity of superficial interneurons in the larval zebrafish tectum
Presynaptic NMDARs cooperate with local spikes toward GABA release from the reciprocal olfactory bulb granule cell spine
The integration of Gaussian noise by long-range amygdala inputs in frontal circuit promotes fear learning in mice
Local Postsynaptic Signaling on Slow Time Scales in Reciprocal Olfactory Bulb Granule Cell Spines Matches Asynchronous Release
Large-Scale 3D Two-Photon Imaging of Molecularly Identified CA1 Interneuron Dynamics in Behaving Mice
LTP Induction Boosts Glutamate Spillover by Driving Withdrawal of Perisynaptic Astroglia
Dendritic integration in olfactory bulb granule cells upon simultaneous multispine activation: Low thresholds for nonlocal spiking activity
An Optical Illusion Pinpoints an Essential Circuit Node for Global Motion Processing
Cell Types of the Human Retina and Its Organoids at Single-Cell Resolution
Input-Output Relationship of CA1 Pyramidal Neurons Reveals Intact Homeostatic Mechanisms in a Mouse Model of Fragile X Syndrome
Effect of allosteric inhibition of non-muscle myosin 2 on its intracellular diffusion
A High-Resolution Method for Quantitative Molecular Analysis of Functionally Characterized Individual Synapses
Restoring light sensitivity using tunable near-infrared sensors
Circuit-specific dendritic development in the piriform cortex
Fluorescence lifetime imaging reveals regulation of presynaptic Ca2+ by glutamate uptake and mGluRs, but not somatic voltage in cortical neurons
Co-electrospun polysuccinimide/poly(vinyl alcohol) composite meshes for tissue engineering
Local Resting Ca2+ Controls the Scale of Astroglial Ca2+ Signals
Dentate gyrus circuits for encoding, retrieval and discrimination of episodic memories
Transparent, low-autofluorescence microECoG device for simultaneous Ca2+ imaging and cortical electrophysiology in vivo
Microglia monitor and protect neuronal function via specialized somatic purinergic junctions
Precapillary sphincters maintain perfusion in the cerebral cortex
Dendritic action potentials and computation in human layer 2/3 cortical neurons
2019
High and asymmetric somato-dendritic coupling of V1 layer 5 neurons independent of visual stimulation and locomotion
Free thiol groups on poly(aspartamide) based hydrogels facilitate tooth-derived progenitor cell proliferation and differentiation
Dendritic inhibition differentially regulates excitability of dentate gyrus parvalbumin-expressing interneurons and granule cells
Targeted Cortical Manipulation of Auditory Perception
Dendritic NMDA receptors in parvalbumin neurons enable strong and stable neuronal assemblies
Method for spike detection from microelectrode array recordings contaminated by artifacts of simultaneous two-photon imaging
Altered dendritic spine function and integration in a mouse model of fragile X syndrome
A silicon-based spiky probe providing improved cell accessibility during in vitro slice recordings
Fluorescence-Based Quantitative Synapse Analysis for Cell Type-Specific Connectomics
HCN channel-mediated neuromodulation can control action potential velocity and fidelity in central axons
Sensory Stimulation-Induced Astrocytic Calcium Signaling in Electrically Silent Ischemic Penumbra
Response of the neurovascular unit to brain metastatic breast cancer cells
Parsing Out the Variability of Transmission at Central Synapses Using Optical Quantal Analysis
A genetically encoded fluorescent sensor for in vivo imaging of GABA
CLARITY analysis of the Cl/pH sensor expression in the brain of transgenic mice
Vasopressin Cells in the Rodent Olfactory Bulb Resemble Non-Bursting Superficial Tufted Cells and Are Primarily Inhibited upon Olfactory Nerve Stimulation
Glutamate Imaging Reveals Multiple Sites of Stochastic Release in the CA3 Giant Mossy Fiber Boutons
Polymer microchamber arrays for geometry-controlled drug release: a functional study in human cells of neuronal phenotype
Neuronal Architecture of a Visual Center that Processes Optic Flow
Optically Induced Calcium-Dependent Gene Activation and Labeling of Active Neurons Using CaMPARI and Cal-Light
Context-dependent signaling of coincident auditory and visual events in primary visual cortex
Multiple Two-Photon Targeted Whole-Cell Patch-Clamp Recordings From Monosynaptically Connected Neurons in vivo
Semaphorin4D Induces Inhibitory Synapse Formation by Rapid Stabilization of Presynaptic Boutons via MET Coactivation
Improved spike inference accuracy by estimating the peak amplitude of unitary [Ca2+] transients in weakly GCaMP6f‐expressing hippocampal pyramidal cells
Endocannabinoid Signaling Mediates Local Dendritic Coordination between Excitatory and Inhibitory Synapses
Agouti-Related Protein 2 Is a New Player in the Teleost Stress Response System
Cortical recruitment determines learning dynamics and strategy
Abstract
Salience is a broad and widely used concept in neuroscience whose neuronal correlates, however, remain elusive. In behavioral conditioning, salience is used to explain various effects, such as stimulus overshadowing, and refers to how fast and strongly a stimulus can be associated with a conditioned event. Here, we identify sounds of equal intensity and perceptual detectability, which due to their spectro-temporal content recruit different levels of population activity in mouse auditory cortex. When using these sounds as cues in a Go/NoGo discrimination task, the degree of cortical recruitment matches the salience parameter of a reinforcement learning model used to analyze learning speed. We test an essential prediction of this model by training mice to discriminate light-sculpted optogenetic activity patterns in auditory cortex, and verify that cortical recruitment causally determines association or overshadowing of the stimulus components. This demonstrates that cortical recruitment underlies major aspects of stimulus salience during reinforcement learning.
Multiplex imaging relates quantal glutamate release to presynaptic Ca2+ homeostasis at multiple synapses in situ
Rapid active zone remodeling consolidates presynaptic potentiation
Population dynamics and entrainment of basal ganglia pacemakers are shaped by their dendritic arbors
A compact holographic projector module for high-resolution 3D multi-site two-photon photostimulation
Functional Synaptic Architecture of Callosal Inputs in Mouse Primary Visual Cortex
Summary
Coincidence Detection within the Excitable Rat Olfactory Bulb Granule Cell Spines
Activity Patterns in the Neuropil of Striatal Cholinergic Interneurons in Freely Moving Mice Represent Their Collective Spiking Dynamics
2018
The First Postlesion Minutes: An In Vivo Study of Extravasation and Perivascular Astrocytes Following Cerebral Lesions in Various Experimental Mouse Models
The Low-Threshold Calcium Channel Cav3.2 Mediates Burst Firing of Mature Dentate Granule Cells
Stimulation-induced increases in cerebral blood flow and local capillary vasoconstriction depend on conducted vascular responses
Spontaneous astrocytic Ca2+ activity abounds in electrically suppressed ischemic penumbra of aged mice
Microglia control the spread of neurotropic virus infection via P2Y12 signalling and recruit monocytes through P2Y12-independent mechanisms
Multimodal Characterization of Neural Networks Using Highly Transparent Electrode Arrays
Monitoring Ca2+ elevations in individual astrocytes upon local release of amyloid beta in acute brain slices
Large-conductance Ca2+-activated potassium channels are potently involved in the inverse neurovascular response to spreading depolarization
Single synaptic inputs drive high-precision action potentials in parvalbumin expressing GABA-ergic cortical neurons in vivo
Parallel emergence of stable and dynamic memory engrams in the hippocampus
Disentangling astroglial physiology with a realistic cell model in silico
Dendrite-Specific Amplification of Weak Synaptic Input during Network Activity In Vivo
Parvalbumin-Interneuron Output Synapses Show Spike-Timing-Dependent Plasticity that Contributes to Auditory Map Remodeling
Topography of a Visuomotor Transformation
Nano-engineered microcapsules boost the treatment of persistent pain
Abstract
Persistent pain remains a major health issue: common treatments relying on either repeated local injections or systemic drug administration are prone to concomitant side-effects. It is thought that an alternative could be a multifunctional cargo system to deliver medicine to the target site and release it over a prolonged time window. We nano-engineered microcapsules equipped with adjustable cargo release properties and encapsulated the sodium-channel blocker QX-314 using the layer-by-layer (LbL) technology. First, we employed single-cell electrophysiology to establish in vitro that microcapsule application can dampen neuronal excitability in a controlled fashion. Secondly, we used two-photon excitation imaging to monitor and adjust long-lasting release of encapsulated cargo in target tissue in situ. Finally, we explored an established peripheral inflammation model in rodents to find that a single local injection of QX-314-containing microcapsules could provide robust pain relief lasting for over a week. This was accompanied by a recovery of the locomotive deficit and the amelioration of anxiety in animals with persistent inflammation. Post hoc immunohistology confirmed biodegradation of microcapsules over a period of several weeks. The overall remedial effect lasted 10–20 times longer than that of a single focal drug injection. It depended on the QX-314 encapsulation levels, involved TRPV1-channel-dependent cell permeability of QX-314, and showed no detectable side-effects. Our data suggest that nano-engineered encapsulation provides local drug delivery suitable for prolonged pain relief, which could be highly advantageous compared to existing treatments.
Alterations in the properties of the cell membrane due to glycosphingolipid accumulation in a model of Gaucher disease
Abstract
Gaucher disease is a lysosomal storage disease characterized by the malfunction of glucocerebrosidase resulting in the accumulation of glucosylceramide and other sphingolipids in certain cells. Although the disease symptoms are usually attributed to the storage of undigested substrate in lysosomes, here we show that glycosphingolipids accumulating in the plasma membrane cause profound changes in the properties of the membrane. The fluidity of the sphingolipid-enriched membrane decreased accompanied by the enlargement of raft-like ordered membrane domains. The mobility of non-raft proteins and lipids was severely restricted, while raft-resident components were only mildly affected. The rate of endocytosis of transferrin receptor, a non-raft protein, was significantly retarded in Gaucher cells, while the endocytosis of the raft-associated GM1 ganglioside was unaffected. Interferon-γ-induced STAT1 phosphorylation was also significantly inhibited in Gaucher cells. Atomic force microscopy revealed that sphingolipid accumulation was associated with a more compliant membrane capable of producing an increased number of nanotubes. The results imply that glycosphingolipid accumulation in the plasma membrane has significant effects on membrane properties, which may be important in the pathogenesis of Gaucher disease.
Electrical coupling between A17 cells enhances reciprocal inhibitory feedback to rod bipolar cells
Abstract
A17 amacrine cells are an important part of the scotopic pathway. Their synaptic varicosities receive glutamatergic inputs from rod bipolar cells (RBC) and release GABA onto the same RBC terminal, forming a reciprocal feedback that shapes RBC depolarization. Here, using patch-clamp recordings, we characterized electrical coupling between A17 cells of the rat retina and report the presence of strongly interconnected and non-coupled A17 cells. In coupled A17 cells, evoked currents preferentially flow out of the cell through GJs and cross-synchronization of presynaptic signals in a pair of A17 cells is correlated to their coupling degree. Moreover, we demonstrate that stimulation of one A17 cell can induce electrical and calcium transients in neighboring A17 cells, thus confirming a functional flow of information through electrical synapses in the A17 coupled network. Finally, blocking GJs caused a strong decrease in the amplitude of the inhibitory feedback onto RBCs. We therefore propose that electrical coupling between A17 cells enhances feedback onto RBCs by synchronizing and facilitating GABA release from inhibitory varicosities surrounding each RBC axon terminal. GJs between A17 cells are therefore critical in shaping the visual flow through the scotopic pathway.
Monitoring intracellular nanomolar calcium using fluorescence lifetime imaging
Abstract
Nanomolar-range fluctuations of intracellular [Ca2+] are critical for brain cell function but remain difficult to measure. We have advanced a microscopy technique to monitor intracellular [Ca2+] in individual cells in acute brain slices (also applicable in vivo) using fluorescence lifetime imaging (FLIM) of the Ca2+-sensitive fluorescent indicator Oregon Green BAPTA1 (OGB-1). The OGB-1 fluorescence lifetime is sensitive to [Ca2+] within the 10–500 nM range but not to other factors such as viscosity, temperature, or pH. This protocol describes the requirements, setup, and calibration of the FLIM system required for OGB-1 imaging. We provide a step-by-step procedure for whole-cell OGB-1 loading and two-photon FLIM. We also describe how to analyze the obtained FLIM data using total photon count and gated-intensity record, a ratiometric photon-counting approach that provides a highly improved signal-to-noise ratio and greater sensitivity of absolute [Ca2+] readout. We demonstrate our technique in nerve cells in situ, and it is adaptable to other cell types and fluorescent indicators. This protocol requires a basic understanding of FLIM and experience in single-cell electrophysiology and cell imaging. Setting up the FLIM system takes ∼2 d, and OGB-1 loading, imaging, and data analysis take 2 d.
Precisely Timed Nicotinic Activation Drives SST Inhibition in Neocortical Circuits
Summary
Sleep, waking, locomotion, and attention are associated with cell-type-specific changes in neocortical activity. The effect of brain state on circuit output requires understanding of how neuromodulators influence specific neuronal classes and their synapses, with normal patterns of neuromodulator release from endogenous sources. We investigated the state-dependent modulation of a ubiquitous feedforward inhibitory motif in mouse sensory cortex, local pyramidal (Pyr) inputs onto somatostatin (SST)-expressing interneurons. Paired whole-cell recordings in acute brain slices and in vivo showed that Pyr-to-SST synapses are remarkably weak, with failure rates approaching 80%. Pharmacological screening revealed that cholinergic agonists uniquely enhance synaptic efficacy. Brief, optogenetically gated acetylcholine release dramatically enhanced Pyr-to-SST input, via nicotinic receptors and presynaptic PKA signaling. Importantly, endogenous acetylcholine release preferentially activated nicotinic, not muscarinic, receptors, thus differentiating drug effects from endogenous neurotransmission. Brain state- and synapse-specific unmasking of synapses may be a powerful way to functionally rewire cortical circuits dependent on behavioral demands.
Caldendrin Directly Couples Postsynaptic Calcium Signals to Actin Remodeling in Dendritic Spines
Summary
Compartmentalization of calcium-dependent plasticity allows for rapid actin remodeling in dendritic spines. However, molecular mechanisms for the spatio-temporal regulation of filamentous actin (F-actin) dynamics by spinous Ca2+-transients are still poorly defined. We show that the postsynaptic Ca2+ sensor caldendrin orchestrates nano-domain actin dynamics that are essential for actin remodeling in the early phase of long-term potentiation (LTP). Steep elevation in spinous [Ca2+]idisrupts an intramolecular interaction of caldendrin and allows cortactin binding. The fast on and slow off rate of this interaction keeps cortactin in an active conformation, and protects F-actin at the spine base against cofilin-induced severing. Caldendrin gene knockout results in higher synaptic actin turnover, altered nanoscale organization of spinous F-actin, defects in structural spine plasticity, LTP, and hippocampus-dependent learning. Collectively, the data indicate that caldendrin-cortactin directly couple [Ca2+]i to preserve a minimal F-actin pool that is required for actin remodeling in the early phase of LTP.
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[custom_date] => 22nd February 2018 [post_or_link] => link [link_to_publication] => https://doi.org/10.1016/j.neuron.2018.01.046 ) Super Resolution Imaging of the Extracellular Space in Living Brain Tissue
Summary
Voltage Gated Calcium Channel Activation by Backpropagating Action Potentials Downregulates NMDAR Function
The majority of excitatory synapses are located on dendritic spines of cortical glutamatergic neurons. In spines, compartmentalized Ca2+ signals transduce electrical activity into specific long-term biochemical and structural changes. Action potentials (APs) propagate back into the dendritic tree and activate voltage gated Ca2+ channels (VGCCs). For spines, this global mode of spine Ca2+ signaling is a direct biochemical feedback of suprathreshold neuronal activity. We previously demonstrated that backpropagating action potentials (bAPs) result in long-term enhancement of spine VGCCs. This activity-dependent VGCC plasticity results in a large interspine variability of VGCC Ca2+ influx. Here, we investigate how spine VGCCs affect glutamatergic synaptic transmission. We combined electrophysiology, two-photon Ca2+ imaging and two-photon glutamate uncaging in acute brain slices from rats. T- and R-type VGCCs were the dominant depolarization-associated Ca2+conductances in dendritic spines of excitatory layer 2 neurons and do not affect synaptic excitatory postsynaptic potentials (EPSPs) measured at the soma. Using two-photon glutamate uncaging, we compared the properties of glutamatergic synapses of single spines that express different levels of VGCCs. While VGCCs contributed to EPSP mediated Ca2+ influx, the amount of EPSP mediated Ca2+ influx is not determined by spine VGCC expression. On a longer timescale, the activation of VGCCs by bAP bursts results in downregulation of spine NMDAR function.
[content] => [custom_date] => 23rd April 2018 [post_or_link] => link [link_to_publication] => https://doi.org/10.3389/fncel.2018.00109 [author] => Anne-Kathrin Theis, Balazs Rozsa, Gergely Katona, Dietmar Schmitz and Friedrich W. Johenning ) High efficiency two-photon uncaging coupled by the correction of spontaneous hydrolysis.
Abstract
Two-photon (TP) uncaging of neurotransmitter molecules is the method of choice to mimic and study the subtleties of neuronal communication either in the intact brain or in slice preparations. However, the currently available caged materials are just at the limit of their usability and have several drawbacks. The local and focal nature of their use may for example be jeopardized by a high spontaneous hydrolysis rate of the commercially available compounds with increased photochemical release rate. Here, using quantum chemical modelling we show the mechanisms of hydrolysis and two-photon activation, and synthesized more effective caged compounds. Furthermore, we have developed a new enzymatic elimination method removing neurotransmitters inadvertently escaping from their compound during experiment. This method, usable both in one and two-photon experiments, allows for the use of materials with an increased rate of photochemical release. The efficiency of the new compound and the enzymatic method and of the new compound are demonstrated in neurophysiological experiments.
2017
σ1-Receptor Agonism Protects against Renal Ischemia-Reperfusion Injury
Suppression of SNARE‐dependent exocytosis in retinal glial cells and its effect on ischemia‐induced neurodegeneration
Dendritic Arborization Patterns of Small Juxtaglomerular Cell Subtypes within the Rodent Olfactory Bulb
Two-Photon Na+ Imaging Reports Somatically Evoked Action Potentials in Rat Olfactory Bulb Mitral and Granule Cell Neurites
Target Cell Type-Dependent Differences in Ca2+ Channel Function Underlie Distinct Release Probabilities at Hippocampal Glutamatergic Terminals
Synaptic plasticity through activation of GluA3-containing AMPA-receptors
Metaplasticity at CA1 Synapses by Homeostatic Control of Presynaptic Release Dynamics
Neuroplastin and Basigin Are Essential Auxiliary Subunits of Plasma Membrane Ca2+-ATPases and Key Regulators of Ca2+ Clearance
Loss of Saltation and Presynaptic Action Potential Failure in Demyelinated Axons
Cell-type–specific inhibition of the dendritic plateau potential in striatal spiny projection neurons
Linking Neurons to Network Function and Behavior by Two-Photon Holographic Optogenetics and Volumetric Imaging
An optogenetic toolbox for unbiased discovery of functionally connected cells in neural circuits
Monitoring single-synapse glutamate release and presynaptic calcium concentration in organised brain tissue
Causal evidence for retina-dependent and -independent visual motion computations in mouse cortex
Extensive astrocyte synchronization advances neuronal coupling in slow wave activity in vivo
Imaging membrane potential changes from dendritic spines using computer-generated holography
Calcineurin-inhibition Results in Upregulation of Local Renin and Subsequent Vascular Endothelial Growth Factor Production in Renal Collecting Ducts
Biodegradation and Osteosarcoma Cell Cultivation on Poly(aspartic acid) Based Hydrogels
Amyloid-β effects on synapses and memory require AMPA receptor subunit GluA3
Sex differences in renin response and changes of capillary diameters after renal ischemia/reperfusion injury
Dopamine elevates and lowers astroglial Ca2+ through distinct pathways depending on local synaptic circuitry
All‐optical functional synaptic connectivity mapping in acute brain slices using the calcium integrator CaMPARI
Fast 3D Imaging of Spine, Dendritic, and Neuronal Assemblies in Behaving Animals
Temporal asymmetries in auditory coding and perception reflect multi-layered nonlinearities
Accurate spike estimation from noisy calcium signals for ultrafast three-dimensional imaging of large neuronal populations in vivo
Astrocytic GABA transporter activity modulates excitatory neurotransmission
Microglia protect against brain injury and their selective elimination dysregulates neuronal network activity after stroke
Correlated Synaptic Inputs Drive Dendritic Calcium Amplification and Cooperative Plasticity during Clustered Synapse Development
Plasticity of intrinsic excitability in mature granule cells of the dentate gyrus
Strength and duration of perisomatic GABAergic inhibition depend on distance between synaptically connected cells
Visualization of Calcium Dynamics in Kidney Proximal Tubules
Recurrent seizure-like events are associated with coupled astroglial synchronization
Dendritic patch-clamp recordings from cerebellar granule cells demonstrate electrotonic compactness
Modeling of in vivo acousto-optic two-photon imaging of the retina in the human eye
Palmitoylation of LIM Kinase-1 ensures spine-specific actin polymerization and morphological plasticity
A Visual Pathway for Looming-Evoked Escape in Larval Zebrafish
In Vivo Monosynaptic Excitatory Transmission between Layer 2 Cortical Pyramidal Neurons
Localized Neuron Stimulation with Organic Electrochemical Transistors on Delaminating Depth Probes
Matching Cell Type to Function in Cortical Circuits
Time-Resolved Imaging Reveals Heterogeneous Landscapes of Nanomolar Ca2+ in Neurons and Astroglia
Electrical behaviour of dendritic spines as revealed by voltage imaging
Tonic endocannabinoid-mediated modulation of GABA release is independent of the CB1 content of axon terminals
Single-cell–initiated monosynaptic tracing reveals layer-specific cortical network modules
Unitary GABAergic volume transmission from individual interneurons to astrocytes in the cerebral cortex
A Calcium-Dependent Mechanism of Neuronal Memory
Ryanodine Receptor Activation Induces Long-Term Plasticity of Spine Calcium Dynamics
Reduced endogenous Ca2+ buffering speeds active zone Ca2+ signaling
Quantitation of various indolinyl caged glutamates as their o-phthalaldehyde derivatives by high performance liquid chromatography coupled with tandem spectroscopic detections: Derivatization, stoichiometry and stability studies
Molecular Tattoo: Subcellular Confinement of Drug Effects
Sensitization of neonatal rat lumbar motoneuron by the inflammatory pain mediator bradykinin
Local Postsynaptic Voltage-Gated Sodium Channel Activation in Dendritic Spines of Olfactory Bulb Granule Cells
MRZ-99030 – A novel modulator of Aβ aggregation: II – Reversal of Aβ oligomer-induced deficits in long-term potentiation (LTP) and cognitive performance in rats and mice
The kinetics of multibranch integration on the dendritic arbor of CA1 pyramidal neurons
Presynaptic Calcium Channel Inhibition Underlies CB1 Cannabinoid Receptor-Mediated Suppression of GABA Release
Mapping somatosensory connectivity in adult mice using diffusion MRI tractography and super-resolution track density imaging
Joint CP-AMPA and group I mGlu receptor activation is required for synaptic plasticity in dentate gyrus fast-spiking interneurons
Cortical fosGFP Expression Reveals Broad Receptive Field Excitatory Neurons Targeted by POm
Ultrafast Action Potentials Mediate Kilohertz Signaling at a Central Synapse
Dendritic Spikes Induce Ripples in Parvalbumin Interneurons during Hippocampal Sharp Waves
Combined two-photon imaging, electrophysiological, and anatomical investigation of the human neocortex in vitro
Spine neck plasticity regulates compartmentalization of synapses
GnRH Neurons Elaborate a Long-Range Projection with Shared Axonal and Dendritic Functions
Role of RIM1α in short- and long-term synaptic plasticity at cerebellar parallel fibres
The RIP1-Kinase Inhibitor Necrostatin-1 Prevents Osmotic Nephrosis and Contrast-Induced AKI in Mice
Differential Subcellular Targeting of Glutamate Receptor Subtypes during Homeostatic Synaptic Plasticity
Silicon carbide quantum dots for bioimaging
K+ depolarization evokes ATP, adenosine and glutamate release from glia in rat hippocampus: a microelectrode biosensor study
Dendritic Hold and Read: A Gated Mechanism for Short Term Information Storage and Retrieval
Release probability of hippocampal glutamatergic terminals scales with the size of the active zone
Fast two-photon in vivo imaging with three-dimensional random-access scanning in large tissue volumes
Experimental evidence for sparse firing in the neocortex
Parallel optical control of spatiotemporal neuronal spike activity using high-speed digital light processing
Complementary Sensory and Associative Microcircuitry in Primary Olfactory Cortex
Roller Coaster Scanning reveals spontaneous triggering of dendritic spikes in CA1 interneurons
Enhanced Dendritic Action Potential Backpropagation in Parvalbumin-positive Basket Cells During Sharp Wave Activity
An Embedded Subnetwork of Highly Active Neurons in the Neocortex
Random access three-dimensional two-photon microscopy
Differential distribution of NCX1 contributes to spine-dendrite compartmentalization in CA1 pyramidal cells