Dynamics of Population Activity in Rat Sensory Cortex: Network Correlations Predict Anatomical Arrangement and Information Content

Separable codes for read-out of mouse primary visual cortex across attentional states

10.1101/731398 ◽

2019 ◽

Cited By ~ 1

Author(s):

Ashley M. Wilson ◽

Jeffrey M. Beck ◽

Lindsey L. Glickfeld

Keyword(s):

Visual Cortex ◽

Primary Visual Cortex ◽

Activity Patterns ◽

Specific Effect ◽

Sensory Cortex ◽

Evoked Responses ◽

Attentional Modulation ◽

Population Activity ◽

V1 Neurons ◽

Encode Task

AbstractAttentional modulation of neuronal activity in sensory cortex could alter perception by enhancing the local representation of attended stimuli or its behavioral read-out downstream. We tested these hypotheses using a task in which mice are cued on interleaved trials to attend visual or auditory targets. Neurons in primary visual cortex (V1) that encode task stimuli have larger visually-evoked responses when attention is directed toward vision. To determine whether the attention-dependent changes in V1 reflect changes in representation or read-out, we decoded task stimuli and choices from population activity. Surprisingly, both visual and auditory choices can be decoded from V1, but decoding takes advantage of unique activity patterns across modalities. Furthermore, decoding of choices, but not stimuli, is impaired when attention is directed toward the opposite modality. The specific effect on choice suggests behavioral improvements with attention are largely due to targeted read-out of the most informative V1 neurons.

Download Full-text

Syngap1 Dynamically Regulates the Fine-Scale Reorganization of Cortical Circuits in Response to Sensory Experience

10.1101/2020.04.14.041038 ◽

2020 ◽

Author(s):

Nerea Llamosas ◽

Thomas Vaissiere ◽

Camilo Rojas ◽

Sheldon Michaelson ◽

Courtney A. Miller ◽

...

Keyword(s):

Neurodevelopmental Disorders ◽

Cortical Plasticity ◽

Neurodevelopmental Disorder ◽

Spike Timing ◽

Sensory Cortex ◽

Fine Scale ◽

Cortical Circuits ◽

Population Activity ◽

Cellular Processes

AbstractExperience induces complex, neuron-specific changes in population activity within sensory cortex circuits. However, the mechanisms that enable neuron-specific changes within cortical populations remain unclear. To explore the idea that synapse strengthening is involved, we studied fine-scale cortical plasticity in Syngap1 mice, a neurodevelopmental disorder model useful for linking synapse biology to circuit functions. Repeated functional imaging of the same L2/3 somatosensory cortex neurons during single whisker experience revealed that Syngap1 selectively regulated the plasticity of a low-active, or “silent”, neuronal subpopulation. Syngap1 also regulated spike-timing-dependent synaptic potentiation and experience-mediated in vivo synapse bouton formation, but not synaptic depression or bouton elimination in L2/3. Adult re-expression of Syngap1 restored plasticity of “silent” neurons, demonstrating that this gene controls dynamic cellular processes required for population-specific changes to cortical circuits during experience. These findings suggest that abnormal experience-dependent redistribution of cortical population activity may contribute to the etiology of neurodevelopmental disorders.

Download Full-text

Topographic Organization of Correlation Along the Longitudinal and Transverse Axes in Rat Hippocampal CA3 Due to Excitatory Afferents

Frontiers in Computational Neuroscience ◽

10.3389/fncom.2020.588881 ◽

2020 ◽

Vol 14 ◽

Author(s):

Gene J. Yu ◽

Jean-Marie C. Bouteiller ◽

Theodore W. Berger

Keyword(s):

Large Scale ◽

Functional Organization ◽

Mossy Fibers ◽

Perforant Path ◽

Population Activity ◽

Topographic Organization ◽

Spatial Correlation Structure ◽

Neuronal Network Model ◽

Hippocampal Ca3 ◽

Dynamics Of Population

The topographic organization of afferents to the hippocampal CA3 subfield are well-studied, but their role in influencing the spatiotemporal dynamics of population activity is not understood. Using a large-scale, computational neuronal network model of the entorhinal-dentate-CA3 system, the effects of the perforant path, mossy fibers, and associational system on the propagation and transformation of network spiking patterns were investigated. A correlation map was constructed to characterize the spatial structure and temporal evolution of pairwise correlations which underlie the emergent patterns found in the population activity. The topographic organization of the associational system gave rise to changes in the spatial correlation structure along the longitudinal and transverse axes of the CA3. The resulting gradients may provide a basis for the known functional organization observed in hippocampus.

Download Full-text

Encoding of reward expectation by monkey anterior insular neurons

Journal of Neurophysiology ◽

10.1152/jn.00282.2011 ◽

2012 ◽

Vol 107 (11) ◽

pp. 2996-3007 ◽

Cited By ~ 20

Author(s):

Takashi Mizuhiki ◽

Barry J. Richmond ◽

Munetaka Shidara

Keyword(s):

Anterior Insula ◽

Reward Schedule ◽

Population Activity ◽

Visual Cue ◽

Current Trial ◽

Reward Seeking ◽

Reward Delivery ◽

Expected Outcome ◽

Schedule Task ◽

Dynamics Of Population

The insula, a cortical brain region that is known to encode information about autonomic, visceral, and olfactory functions, has recently been shown to encode information during reward-seeking tasks in both single neuronal recording and functional magnetic resonance imaging studies. To examine the reward-related activation, we recorded from 170 single neurons in anterior insula of 2 monkeys during a multitrial reward schedule task, where the monkeys had to complete a schedule of 1, 2, 3, or 4 trials to earn a reward. In one block of trials a visual cue indicated whether a reward would or would not be delivered in the current trial after the monkey successfully detected that a red spot turned green, and in other blocks the visual cue was random with respect to reward delivery. Over one-quarter of 131 responsive neurons were activated when the current trial would (certain or uncertain) be rewarded if performed correctly. These same neurons failed to respond in trials that were certain, as indicated by the cue, to be unrewarded. Another group of neurons responded when the reward was delivered, similar to results reported previously. The dynamics of population activity in anterior insula also showed strong signals related to knowing when a reward is coming. The most parsimonious explanation is that this activity codes for a type of expected outcome, where the expectation encompasses both certain and uncertain rewards.

Download Full-text

Applications of Scanning Microscopy in Biomedical Research

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100101517 ◽

1968 ◽

Vol 26 ◽

pp. 354-355

Author(s):

T. L. Hayes

Keyword(s):

Information Content ◽

Biomedical Research ◽

Biomedical Applications ◽

Three Dimensional ◽

Dental Enamel ◽

Resolving Power ◽

Whole Mount ◽

Two Parameters ◽

Content Information ◽

Sectioned Tissue

Biomedical applications of the scanning electron microscope (SEM) have increased in number quite rapidly over the last several years. Studies have been made of cells, whole mount tissue, sectioned tissue, particles, human chromosomes, microorganisms, dental enamel and skeletal material. Many of the advantages of using this instrument for such investigations come from its ability to produce images that are high in information content. Information about the chemical make-up of the specimen, its electrical properties and its three dimensional architecture all may be represented in such images. Since the biological system is distinctive in its chemistry and often spatially scaled to the resolving power of the SEM, these images are particularly useful in biomedical research.In any form of microscopy there are two parameters that together determine the usefulness of the image. One parameter is the size of the volume being studied or resolving power of the instrument and the other is the amount of information about this volume that is displayed in the image. Both parameters are important in describing the performance of a microscope. The light microscope image, for example, is rich in information content (chemical, spatial, living specimen, etc.) but is very limited in resolving power.

Download Full-text

Hair cell changes after cationic stimulation of corti's organ

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100155967 ◽

1989 ◽

Vol 47 ◽

pp. 798-799

Author(s):

Cesar D. Fermin ◽

Hans-Peter Zenner

Keyword(s):

Organ Of Corti ◽

Cross Sectional ◽

Surface Areas ◽

High K ◽

Anatomical Arrangement ◽

Cell Cytosol ◽

High Concentrations ◽

K Concentration ◽

Cell Changes

Contraction of outer and inner hair cells (OHC&IHC) in the Organ of Corti (OC) of the inner ear is necessary for sound transduction. Getting at HC in vivo preparations is difficult. Thus, isolated HCs have been used to study OHC properties. Even though viability has been shown in isolated (iOHC) preparations by good responses to current and cationic stimulation, the contribution of adjoining cells can not be explained with iOHC preparations. This study was undertaken to examine changes in the OHC after expossure of the OHC to high concentrations of potassium (K) and sodium (Na), by carefully immersing the OC in either artifical endolymph or perilymph. After K and Na exposure, OCs were fixed with 3% glutaraldehyde, post-fixed in osmium, separated into base, middle and apex and embedded in Araldite™. One μm thick sections were prepared for analysis with the light and E.M. Cross sectional areas were measured with Bioquant™ software.Potassium and sodium both cause isolated guinea pig OHC to contract. In vivo high K concentration may cause uncontrolled and sustained contractions that could contribute to Meniere's disease. The behavior of OHC in the vivo setting might be very different from that of iOHC. We show here changes of the cell cytosol and cisterns caused by K and Na to OHC in situs. The table below shows results from cross sectional area measurements of OHC from OC that were exposed to either K or Na. As one would expect, from the anatomical arrangement of the OC, OHC#l that are supported by rigid tissue would probably be displaced (move) less than those OHC located away from the pillar. Surprisingly, cells in the middle turn of the cochlea changed their surface areas more than those at either end of the cochlea. Moreover, changes in surface area do not seem to differ between K and Na treated OCs.

Download Full-text