scholarly journals Optogenetic astrocyte activation modulates response selectivity of visual cortex neurons in vivo

2014 ◽  
Vol 5 (1) ◽  
Author(s):  
Gertrudis Perea ◽  
Aimei Yang ◽  
Edward S. Boyden ◽  
Mriganka Sur
Keyword(s):  
Visual Cortex ◽  
Astrocyte Activation ◽  
Visual Cortex Neurons

Comparison of discharge variability in vitro and in vivo in cat visual cortex neurons

1996 ◽  
Vol 75 (5) ◽  
pp. 1806-1814 ◽  
Author(s):  
G. R. Holt ◽  
W. R. Softky ◽  
C. Koch ◽  
R. J. Douglas
Keyword(s):  
Visual Cortex ◽  
Background Activity ◽  
Visual Stimuli ◽  
Constant Current ◽  
Interspike Intervals ◽  
Integrate And Fire ◽  
A New Technique ◽  
Visual Cortex Neurons

1. In neocortical slices, the majority of neurons fire quite regularly in response to constant current injections. But neurons in the intact animal fire irregularly in response to constant current injection as well as to visual stimuli. 2. To quantify this observation, we developed a new measure of variability, which compares only adjacent interspike intervals and is therefore less sensitive to rate variations than existing measures such as the coefficient of variation of interspike intervals. 3. We find that the variability of firing is much higher in cells of primary visual cortex in the anesthetized cat than in slice. The response to current injected from an intracellular electrode in vivo is also variable, but slightly more regular and less bursty than in response to visual stimuli. 4. Using a new technique for analyzing the variability of integrate-and-fire neurons, we prove that this behavior is consistent with a simple integrate-and-fire model receiving a large amount of synaptic background activity, but not with a noisy spiking mechanism.

scholarly journals Locally coordinated synaptic plasticity shapes cell-wide plasticity of visual cortex neurons in vivo

2018 ◽  
Author(s):  
Sami El-Boustani ◽  
Jacque P K Ip ◽  
Vincent Breton-Provencher ◽  
Hiroyuki Okuno ◽  
Haruhiko Bito ◽  
...  
Keyword(s):  
Synaptic Plasticity ◽  
Visual Cortex ◽  
Spike Timing ◽  
Monocular Deprivation ◽  
Early Gene ◽  
Neuronal Responses ◽  
Functional Changes ◽  
Targeted Expression ◽  
Visual Cortex Neurons

AbstractPlasticity of cortical responses involves activity-dependent changes at synapses, but the manner in which different forms of synaptic plasticity act together to create functional changes in neuronal responses remains unknown. Here we show that spike-timing induced receptive field plasticity of individual visual cortex neurons in vivo is anchored by increases in synaptic strength of identified spines, and is accompanied by a novel decrease in the strength of adjacent spines on a slower time scale. The locally coordinated potentiation and depression of spines involves prominent AMPA receptor redistribution via targeted expression of the immediate early gene Arc. Similar changes accompany recovery of eye-specific responses following monocular deprivation. These findings demonstrate that Hebbian strengthening of activated synapses and heterosynaptic weakening of adjacent synapses, in dendrites with heterogeneous synaptic inputs, co-operatively orchestrate cell-wide plasticity of functional neuronal responses.One Sentence SummaryArc-mediated local synaptic plasticity regulates reorganization of synaptic responses on dendritic stretches to mediate functional plasticity of neuronal responses in vivo.

scholarly journals Locally coordinated synaptic plasticity of visual cortex neurons in vivo

Science ◽  
2018 ◽  
Vol 360 (6395) ◽  
pp. 1349-1354 ◽  
Author(s):  
Sami El-Boustani ◽  
Jacque P. K. Ip ◽  
Vincent Breton-Provencher ◽  
Graham W. Knott ◽  
Hiroyuki Okuno ◽  
...  
Keyword(s):  
Synaptic Plasticity ◽  
Visual Cortex ◽  
Spike Timing ◽  
Early Gene ◽  
Functional Changes ◽  
Cortical Responses ◽  
Targeted Expression ◽  
Visual Cortex Neurons ◽  
Activity Dependent

Plasticity of cortical responses in vivo involves activity-dependent changes at synapses, but the manner in which different forms of synaptic plasticity act together to create functional changes in neurons remains unknown. We found that spike timing–induced receptive field plasticity of visual cortex neurons in mice is anchored by increases in the synaptic strength of identified spines. This is accompanied by a decrease in the strength of adjacent spines on a slower time scale. The locally coordinated potentiation and depression of spines involves prominent AMPA receptor redistribution via targeted expression of the immediate early gene product Arc. Hebbian strengthening of activated synapses and heterosynaptic weakening of adjacent synapses thus cooperatively orchestrate cell-wide plasticity of functional neuronal responses.

scholarly journals Involvement of HECTD1 in LPS-induced astrocyte activation via σ-1R-JNK/p38-FOXJ2 axis

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ying Tang ◽  
Mengchun Zhou ◽  
Rongrong Huang ◽  
Ling Shen ◽  
Li Yang ◽  
...  
Keyword(s):  
Inflammatory Responses ◽  
Astrocyte Activation ◽  
Hect Domain ◽  
P38 Inhibitor ◽  
Ubiquitin Protein Ligase ◽  
Primary Mouse ◽  
Lps Treatment

Abstract Background Astrocytes participate in innate inflammatory responses within the mammalian central nervous system (CNS). HECT domain E3 ubiquitin protein ligase 1 (HECTD1) functions during microglial activation, suggesting a connection with neuroinflammation. However, the potential role of HECTD1 in astrocytes remains largely unknown. Results Here, we demonstrated that HECTD1 was upregulated in primary mouse astrocytes after 100 ng/ml lipopolysaccharide (LPS) treatment. Genetic knockdown of HECTD1 in vitro or astrocyte-specific knockdown of HECTD1 in vivo suppressed LPS-induced astrocyte activation, whereas overexpression of HECTD1 in vitro facilitated LPS-induced astrocyte activation. Mechanistically, we established that LPS activated σ-1R-JNK/p38 pathway, and σ-1R antagonist BD1047, JNK inhibitor SP600125, or p38 inhibitor SB203580 reversed LPS-induced expression of HECTD1, thus restored LPS-induced astrocyte activation. In addition, FOXJ2 functioned as a transcription factor of HECTD1, and pretreatment of primary mouse astrocytes with BD1047, SB203580, and SP600125 significantly inhibited LPS-mediated translocation of FOXJ2 into the nucleus. Conclusions Overall, our present findings suggest that HECTD1 participates in LPS-induced astrocyte activation by activation of σ-1R-JNK/p38-FOXJ2 pathway and provide a potential therapeutic strategy for neuroinflammation induced by LPS or any other neuroinflammatory disorders.

scholarly journals Myelin densities in retinotopically defined dorsal visual areas of the macaque

2021 ◽  
Author(s):  
Xiaolian Li ◽  
Qi Zhu ◽  
Wim Vanduffel
Keyword(s):  
Visual Cortex ◽  
Visual Field ◽  
Cortical Thickness ◽  
New World Monkeys ◽  
Isotropic Resolution ◽  
Density Mapping ◽  
Area V2 ◽  
Visual Areas ◽  
Density Results

AbstractThe visuotopic organization of dorsal visual cortex rostral to area V2 in primates has been a longstanding source of controversy. Using sub-millimeter phase-encoded retinotopic fMRI mapping, we recently provided evidence for a surprisingly similar visuotopic organization in dorsal visual cortex of macaques compared to previously published maps in New world monkeys (Zhu and Vanduffel, Proc Natl Acad Sci USA 116:2306–2311, 2019). Although individual quadrant representations could be robustly delineated in that study, their grouping into hemifield representations remains a major challenge. Here, we combined in-vivo high-resolution myelin density mapping based on MR imaging (400 µm isotropic resolution) with fine-grained retinotopic fMRI to quantitatively compare myelin densities across retinotopically defined visual areas in macaques. Complementing previously documented differences in populational receptive-field (pRF) size and visual field signs, myelin densities of both quadrants of the dorsolateral posterior area (DLP) and area V3A are significantly different compared to dorsal and ventral area V3. Moreover, no differences in myelin density were observed between the two matching quadrants belonging to areas DLP, V3A, V1, V2 and V4, respectively. This was not the case, however, for the dorsal and ventral quadrants of area V3, which showed significant differences in MR-defined myelin densities, corroborating evidence of previous myelin staining studies. Interestingly, the pRF sizes and visual field signs of both quadrant representations in V3 are not different. Although myelin density correlates with curvature and anticorrelates with cortical thickness when measured across the entire cortex, exactly as in humans, the myelin density results in the visual areas cannot be explained by variability in cortical thickness and curvature between these areas. The present myelin density results largely support our previous model to group the two quadrants of DLP and V3A, rather than grouping DLP- with V3v into a single area VLP, or V3d with V3A+ into DM.

scholarly journals Functional Biases in Visual Cortex Neurons with Identified Projections to Higher Cortical Targets

2012 ◽  
Vol 22 (4) ◽  
pp. 269-277 ◽  
Author(s):  
Beata Jarosiewicz ◽  
James Schummers ◽  
Wasim Q. Malik ◽  
Emery N. Brown ◽  
Mriganka Sur
Keyword(s):  
Visual Cortex ◽  
Visual Cortex Neurons
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