Orientation and Direction Selectivity of Synaptic Inputs in Visual Cortical Neurons

Monier, Cyril; Chavane, Frédéric; Baudot, Pierre Yves; Graham, Lyle J.; Frégnac, Yves

doi:10.1016/s0896-6273(03)00064-3

Cited by 342 publications

(430 citation statements)

References 66 publications

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“…Other studies have failed to find substantial evidence for orthogonal tuning of inhibition [1,23,46]. Recently, in a comprehensive study, Monier et al [44] have convincingly demonstrated that indeed the orientation tuning of inhibitory synaptic inputs shows substantial variability across the population. While the majority of neurons receive inhibition that peaks at their preferred orientation, a substantial minority receive inhibitory inputs that are orthogonal or oblique to their preferred orientation.…”

Section: Diversity In Subthreshold Tuningmentioning

confidence: 99%

“…There is now substantial experimental support for some of the aspects of this model ( [24,37,50]; see [25] for a recent review). However, there are also numerous features of orientation tuning that this model cannot explain ( [14,21,44,52]; see [63,65] for a review). Several computational models have proposed alternate schemes, based primarily on recurrent amplification of inputs to cortex, that can largely explain the experimental data without recourse to a strict arrangement of thalamocortical projections required by the feedforward model [7,17,64].…”

Section: Orientation Tuning In Primary Visual Cortexmentioning

confidence: 99%

“…It is also possible that the balance of excitation and inhibition plays an important role in regulating the tuning of spiking outputs of neurons near pinwheel centers. There is substantial evidence for shunting inhibition in V1 neurons [1,10,30,44], though the tuning of such inhibition is not entirely clear [1,44]. Shunting inhibition can effectively clamp the membrane potential, which has the effect of reducing the influence of excitatory synaptic inputs, and also reducing the variability of membrane potential [44].…”

Section: Mechanisms Regulating Spike Tuning Near Pinwheel Centersmentioning

confidence: 99%

“…There is substantial evidence for shunting inhibition in V1 neurons [1,10,30,44], though the tuning of such inhibition is not entirely clear [1,44]. Shunting inhibition can effectively clamp the membrane potential, which has the effect of reducing the influence of excitatory synaptic inputs, and also reducing the variability of membrane potential [44]. Thus if there is sufficient inhibition at non-preferred orientations, the membrane potential may be effectively prevented from reaching threshold, despite the large depolarizations seen in neurons near pinwheel centers.…”

Section: Mechanisms Regulating Spike Tuning Near Pinwheel Centersmentioning

confidence: 99%

“…Thus if there is sufficient inhibition at non-preferred orientations, the membrane potential may be effectively prevented from reaching threshold, despite the large depolarizations seen in neurons near pinwheel centers. There is evidence that a substantial portion of V1 neurons receive shunting inhibition that is tuned orthogonal to the preferred orientation of the cell, and such neurons have been hypothesized to be located near pinwheel centers [44]. However, to act as a regulator of firing rate tuning, inhibition need not be orthogonally tuned.…”

Section: Mechanisms Regulating Spike Tuning Near Pinwheel Centersmentioning

confidence: 99%

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Local networks in visual cortex and their influence on neuronal responses and dynamics

Schummers¹,

Mariño²,

Sur³

2004

Journal of Physiology-Paris

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Networks of neurons in the cerebral cortex generate complex outputs that are not simply predicted by their inputs. These emergent responses underlie the function of the cortex. Understanding how cortical networks carry out such transformations requires a description of the responses of individual neurons and of their networks at multiple levels of analysis. We focus on orientation selectivity in primary visual cortex as a model system to understand cortical network computations. Recent experiments in our laboratory and others provide significant insight into how cortical networks generate and maintain orientation selectivity. We first review evidence for the diversity of orientation tuning characteristics in visual cortex. We then describe experiments that combine optical imaging of orientation maps with intracellular and extracellular recordings from individual neurons at known locations in the orientation map. The data indicate that excitatory and inhibitory synaptic inputs are summed across the cortex in a manner that is consistent with simple rules of integration of local inputs. These rules arise from known anatomical projection patterns in visual cortex. We propose that the generation and plasticity of orientation tuning is strongly influenced by local cortical networks-the diversity of these properties arises in part from the diversity of neighbourhood features that derive from the orientation map.

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Section: Diversity In Subthreshold Tuningmentioning

confidence: 99%

Section: Orientation Tuning In Primary Visual Cortexmentioning

confidence: 99%

Section: Mechanisms Regulating Spike Tuning Near Pinwheel Centersmentioning

confidence: 99%

Section: Mechanisms Regulating Spike Tuning Near Pinwheel Centersmentioning

confidence: 99%

Section: Mechanisms Regulating Spike Tuning Near Pinwheel Centersmentioning

confidence: 99%

See 3 more Smart Citations

Local networks in visual cortex and their influence on neuronal responses and dynamics

Schummers¹,

Mariño²,

Sur³

2004

Journal of Physiology-Paris

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Model‐based analysis of excitatory lateral connections in the visual cortex

Buzás

Kovács

Ferecskó

et al. 2006

J of Comparative Neurology

103

151

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Excitatory lateral connections within the primary visual cortex are thought to link neurons with similar receptive field properties. Here we studied whether this rule can predict the distribution of excitatory connections in relation to cortical location and orientation preference in the cat visual cortex. To this end, we obtained orientation maps of areas 17 or 18 using optical imaging and injected anatomical tracers into these regions. The distribution of labeled axonal boutons originating from large populations of excitatory neurons was then analyzed and compared with that of individual pyramidal or spiny stellate cells. We demonstrate that the connection patterns of populations of nearby neurons can be reasonably predicted by Gaussian and von Mises distributions as a function of cortical location and orientation, respectively. The connections were best described by superposition of two components: a spatially extended, orientation-specific and a local, orientation-invariant component. We then fitted the same model to the connections of single cells. The composite pattern of nine excitatory neurons (obtained from seven different animals) was consistent with the assumptions of the model. However, model fits to single cell axonal connections were often poorer and their estimated spatial and orientation tuning functions were highly variable. We conclude that the intrinsic excitatory network is biased to similar cortical locations and orientations but it is composed of neurons showing significant deviations from the population connectivity rule.

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Altered temporal variance and neural synchronization of spontaneous brain activity in anesthesia

Huang

Wang

Zhang

et al. 2014

Human Brain Mapping

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Recent studies at the cellular and regional levels have pointed out the multifaceted importance of neural synchronization and temporal variance of neural activity. For example, neural synchronization and temporal variance has been shown by us to be altered in patients in the vegetative state (VS). This finding nonetheless leaves open the question of whether these abnormalities are specific to VS or rather more generally related to the absence of consciousness. The aim of our study was to investigate the changes of inter- and intra-regional neural synchronization and temporal variance of resting state activity in anesthetic-induced unconsciousness state. Applying an intra-subject design, we compared resting state activity in functional magnetic resonance imaging (fMRI) between awake versus anesthetized states in the same subjects. Replicating previous studies, we observed reduced functional connectivity within the default mode network (DMN) and thalamocortical network in the anesthetized state. Importantly, intra-regional synchronization as measured by regional homogeneity (ReHo) and temporal variance as measured by standard deviation (SD) of the BOLD signal were significantly reduced in especially the cortical midline regions, while increased in the lateral cortical areas in the anesthetized state. We further found significant frequency-dependent effects of SD in the thalamus, which showed abnormally high SD in Slow-5 (0.01-0.027 Hz) in the anesthetized state. Our results show for the first time of altered temporal variance of resting state activity in anesthesia. Combined with our findings in the vegetative state, these findings suggest a close relationship between temporal variance, neural synchronization and consciousness.

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Orientation and Direction Selectivity of Synaptic Inputs in Visual Cortical Neurons

Cited by 342 publications

References 66 publications

Local networks in visual cortex and their influence on neuronal responses and dynamics

Local networks in visual cortex and their influence on neuronal responses and dynamics

Model‐based analysis of excitatory lateral connections in the visual cortex

Altered temporal variance and neural synchronization of spontaneous brain activity in anesthesia

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