scholarly journals Mouse visual cortex areas represent perceptual and semantic features of learned visual categories

2021 ◽  
Author(s):  
Pieter M. Goltstein ◽  
Sandra Reinert ◽  
Tobias Bonhoeffer ◽  
Mark Hübener
Keyword(s):  
Visual Cortex ◽  
Visual Information ◽  
Semantic Content ◽  
Brain Regions ◽  
Semantic Features ◽  
Associative Memories ◽  
Visual Category Learning ◽  
Perceptual Representations ◽  
Mouse Visual Cortex

AbstractAssociative memories are stored in distributed networks extending across multiple brain regions. However, it is unclear to what extent sensory cortical areas are part of these networks. Using a paradigm for visual category learning in mice, we investigated whether perceptual and semantic features of learned category associations are already represented at the first stages of visual information processing in the neocortex. Mice learned categorizing visual stimuli, discriminating between categories and generalizing within categories. Inactivation experiments showed that categorization performance was contingent on neuronal activity in the visual cortex. Long-term calcium imaging in nine areas of the visual cortex identified changes in feature tuning and category tuning that occurred during this learning process, most prominently in the postrhinal area (POR). These results provide evidence for the view that associative memories form a brain-wide distributed network, with learning in early stages shaping perceptual representations and supporting semantic content downstream.

scholarly journals NMDAR-independent acetylcholine, serotonin, and norepinephrine mediated modulation of synaptic eligibility traces into LTD in mice visual cortex

2020 ◽  
Author(s):  
Shumsuzzaman Khan
Keyword(s):  
Visual Cortex ◽  
Ex Vivo ◽  
Brain Slices ◽  
Low Frequency ◽  
Decay Kinetics ◽  
Low Frequency Stimulation ◽  
Long Term Changes ◽  
Frequency Stimulation ◽  
Mouse Visual Cortex

AbstractIn reward-based learning, synaptic eligibility traces are a well-defined theoretical solution for the conversion of initial co-activation of pre and postsynaptic neurons into long-term changes in synaptic strength by reward-linked neuromodulators. However, the types of neuromodulators involved in such a phenomenon in mouse visual cortex remain unknown. To characterize the Ex vivo condition, we used optogenetic stimulation of channelrhodopsin-(ChR2) expressing Cre/Ai32(ChR2-eYFP); Tph2-Cre/Ai32(ChR2-eYFP); Thi-Cre/Ai32(ChR2-eYFP) homozygous mice, which release acetylcholine, serotonin, and norepinephrine, respectively. With these mice it is possible to measure the transformation of eligibility traces into long-term changes by endogenous neuromodulators. Here we delineated that layer 2/3 neurons in the visual cortex showed no LTD after conditioning with paired-pulse low-frequency stimulation (ppLFS; 2Hz, 15 min). However, if conditioning was paired with acetylcholine, serotonin, or norepinephrine release upon 473 nm optical stimulation in brain slices, LTD occurs in every case. Thus, our data suggests a new pathway to connect the gap between stimulus and reward. Moreover, we found that stimulation by theta-glass or metal stimulators evoked IPSC traces with the same amplitudes but differences in decay kinetics, further questioning the appropriate use of stimulators in brain slices for evoking an event.

scholarly journals Transient and localized optogenetic activation of somatostatin-interneurons in mouse visual cortex abolishes long-term cortical plasticity due to vision loss

2018 ◽  
Vol 223 (5) ◽  
pp. 2073-2095 ◽  
Author(s):  
Isabelle Scheyltjens ◽  
Samme Vreysen ◽  
Chris Van den Haute ◽  
Victor Sabanov ◽  
Detlef Balschun ◽  
...  
Keyword(s):  
Visual Cortex ◽  
Vision Loss ◽  
Cortical Plasticity ◽  
Mouse Visual Cortex

scholarly journals Reciprocal Homosynaptic and Heterosynaptic Long-Term Plasticity of Corticogeniculate Projection Neurons in Layer VI of the Mouse Visual Cortex

2013 ◽  
Vol 33 (18) ◽  
pp. 7787-7798 ◽  
Author(s):  
M. K. Arami ◽  
K. Sohya ◽  
A. Sarihi ◽  
B. Jiang ◽  
Y. Yanagawa ◽  
...  
Keyword(s):  
Visual Cortex ◽  
Projection Neurons ◽  
Mouse Visual Cortex ◽  
Layer Vi

scholarly journals mGluR5-dependent acetylcholine, serotonin, and norepinephrine mediated modulation of synaptic eligibility traces into LTD in mice visual cortex

2021 ◽  
Author(s):  
Shumsuzzaman Khan
Keyword(s):  
Visual Cortex ◽  
Ex Vivo ◽  
Brain Slices ◽  
Low Frequency ◽  
Decay Kinetics ◽  
Low Frequency Stimulation ◽  
Long Term Changes ◽  
Frequency Stimulation ◽  
Mouse Visual Cortex

Abstract In reward-based learning, synaptic eligibility traces are a well-defined theoretical solution for the conversion of initial co-activation of pre and postsynaptic neurons into long-term changes in synaptic strength by reward-linked neuromodulators. However, the types of neuromodulators involved in such a phenomenon in mouse visual cortex remain unknown. To characterize the Ex vivo condition, we used optogenetic stimulation of channelrhodopsin-(ChR2) expressing Cre/Ai32(ChR2-eYFP); Tph2-Cre/Ai32(ChR2-eYFP); Thi-Cre/Ai32(ChR2-eYFP) homozygous mice, which release acetylcholine, serotonin, and norepinephrine, respectively. With these mice it is possible to measure the transformation of eligibility traces into long-term changes by endogenous neuromodulators. Here we delineated that layer 2/3 neurons in the visual cortex showed no LTD after conditioning with paired-pulse low-frequency stimulation (ppLFS; 2Hz, 15 min). However, if conditioning was paired with acetylcholine, serotonin, or norepinephrine release upon 473 nm optical stimulation in brain slices, LTD occurs in every case. Thus, our data suggests a new pathway to connect the gap between stimulus and reward. Moreover, we found that stimulation by theta-glass or metal stimulators evoked IPSC traces with the same amplitudes but differences in decay kinetics, further questioning the appropriate use of stimulators in brain slices for evoking an event.

scholarly journals Large-scale algorithmic search identifies stiff and sloppy dimensions in synaptic architectures consistent with murine neocortical wiring

2021 ◽  
Author(s):  
Tarek Jabri ◽  
Jason N MacLean
Keyword(s):  
Visual Cortex ◽  
Large Scale ◽  
Normal Range ◽  
Dynamical Regimes ◽  
Algorithmic Search ◽  
Short And Long Term ◽  
Mouse Visual Cortex ◽  
Parameter Values ◽  
Connectivity Parameter

Complex systems can be defined by "sloppy" dimensions, meaning that their behavior is unmodified by large changes to specific parameter combinations, and "stiff" dimensions whose changes result in considerable modifications. In the case of the neocortex, sloppiness in synaptic architectures would be crucial to allow for the maintenance of spiking dynamics in the normal range despite a diversity of inputs and both short- and long-term changes to connectivity. Using simulations on neural networks with spiking matched to murine visual cortex, we determined the stiff and sloppy parameters of synaptic architectures across three classes of input (brief, continuous, and cyclical). Large-scale algorithmically-generated connectivity parameter values revealed that specific combinations of excitatory and inhibitory connectivity are stiff and that all other architectural details are sloppy. Stiff dimensions are consistent across a range of different input classes with self-sustaining synaptic architectures occupying a smaller subspace as compared to the other input classes. We also find that experimentally estimated connectivity probabilities from mouse visual cortex are similarly stiff and sloppy when compared to the architectures that we identified algorithmically. This suggests that simple statistical descriptions of spiking dynamics are a sufficient and parsimonious description of neocortical activity when examining structure-function relationships at the mesoscopic scale. Moreover, this study provides further evidence of the importance of the interrelationship of excitatory and inhibitory connectivity to establish and maintain stable spiking dynamical regimes in neocortex.

scholarly journals Stability and plasticity of contextual modulation in the mouse visual cortex

2016 ◽  
Author(s):  
Adam Ranson
Keyword(s):  
Visual Cortex ◽  
Activity Level ◽  
Visual Context ◽  
Contextual Modulation ◽  
Long Term Stability ◽  
Highly Active ◽  
Primary Sensory Cortex ◽  
Excitatory Neurons ◽  
Mouse Visual Cortex

SummaryActivity of neurons in primary sensory cortex is shaped by visual and behavioural context. However the long-term stability of the influence of contextual factors in the mature cortex remains poorly understood. To investigate this we used 2-photon calcium imaging to track the influence of surround suppression and locomotion on individual neurons over 14 days. We found that highly active excitatory neurons and PV+ interneurons exhibited relatively stable modulation by visual context. Similarly most neurons exhibited a stable yet distinct degree modulation by locomotion. In contrast less active excitatory neurons exhibited plasticity in visual context influence resulting in increased suppression. These findings suggest that the mature visual cortex possesses stable subnetworks of neurons, differentiated by cell-type and activity level, which have distinctive and stable interactions with sensory and behavioural context, as well as other less active and more labile neurons which are sensitive to visual experience.

scholarly journals Mesoscale correlation structure with single cell resolution during visual coding

2018 ◽  
Author(s):  
Yiyi Yu ◽  
Jeffrey N. Stirman ◽  
Christopher R. Dorsett ◽  
Spencer L. Smith
Keyword(s):  
Visual Cortex ◽  
Receptive Field ◽  
Visual Information ◽  
Functional Organization ◽  
Brain Regions ◽  
Correlation Structure ◽  
Visual Coding ◽  
Cortical Areas ◽  
The Individual ◽  
Higher Visual Areas

AbstractNeural circuitry represents sensory input with patterns of spiking activity. Across brain regions, initial representations are transformed to ultimately drive adaptive behavior. In mammalian neocortex, visual information is processed by primary visual cortex (V1) and multiple higher visual areas (HVAs). The interconnections of these brain regions, over which transformations can occur, span millimeters or more. Shared variability in spiking responses between neurons, called “noise correlations” (NCs), can be due to shared input and/or direct or indirect connectivity. Thus, NCs provide insight into the functional connectivity of neuronal circuits. In this study, we used subcellular resolution, mesoscale field-of-view two-photon calcium imaging to systematically characterize the NCs for pairs of layer 2/3 neurons across V1 and four HVAs (areas LM, LI, AL and PM) of mice. The average NCs for pairs of neurons within or across cortical areas were orders of magnitude larger than trial-shuffled control values. We characterized the modulation of NCs by neuron distance, tuning similarity, receptive field overlap, and stimulus type over millimeter scale distances in mouse visual cortex, within and across V1 and multiple HVAs. NCs were positively correlated with shared tuning and receptive field overlap, even across cortical areas and millimeter length scales. We compared the structure of these NCs to that of hypothetical networks to determine what network types can account for the results. We found that to reproduce the NC networks, neuron connectivity was regulated by both feature similarities and hub mechanism. Overall, these results revealed principles for the functional organization and correlation structure at the individual neuron level across multiple cortical areas, which can inform and constrain computational theories of cortical networks.

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