scholarly journals Variation in Spontaneous Activity and Visual Evoked Response in Primary Visual Cortex of the S334ter-3 Rats

2020 ◽  
Vol 185 ◽  
pp. 03034
Author(s):  
Bojun Hou ◽  
Ke Chen ◽  
Yilei Zhao ◽  
Leanne Lai Hang Chan
Keyword(s):  
Visual Cortex ◽  
Spontaneous Activity ◽  
Primary Visual Cortex ◽  
Dynamic Range ◽  
Signal To Noise Ratio ◽  
Evoked Responses ◽  
Visual Evoked Response ◽  
Classical Receptive Field ◽  
Narrow Dynamic Range ◽  
Visual Evoked

S334ter-3 retinal degeneration (RD) rats have been widely used to investigate degenerative diseases of the retina. In this model, morphological and electrophysiological changes have been observed in the retina, superior colliculus and primary visual cortex (V1). In this study, experimental rats (S334ter-3) carried one copy of the mutant transgene. We measured the extracellular responses in the primary visual cortex to three stimulus contrast levels (spontaneous activity, medium contrast, and high contrast) at the preferred parameters of each recorded cell under classical receptive field (CRF) stimulation. Then we compared the responses (spontaneous activity and the visual evoked responses) in RD rats with those in wildtype rats. Our results show that V1 cells in the RD group exhibit stronger spontaneous activity but weaker stimulus-evoked responses at medium and high contrasts. At the same time, compared with WT group, RD group also showed a narrow dynamic range. These results indicate the decrease in discriminating the stimuli contrast and loss in responses and lower signal to noise ratio after retina degeneration.

Neural Representation of the Luminance and Brightness of a Uniform Surface in the Macaque Primary Visual Cortex

2001 ◽  
Vol 86 (5) ◽  
pp. 2559-2570 ◽  
Author(s):  
Masaharu Kinoshita ◽  
Hidehiko Komatsu
Keyword(s):  
Visual Cortex ◽  
Receptive Field ◽  
Primary Visual Cortex ◽  
Neural Activity ◽  
Dynamic Range ◽  
Neural Representation ◽  
Homogeneous Surface ◽  
V1 Neurons ◽  
Classical Receptive Field ◽  
Multiple Unit

The perceived brightness of a surface is determined not only by the luminance of the surface (local information), but also by the luminance of its surround (global information). To better understand the neural representation of surface brightness, we investigated the effects of local and global luminance on the activity of neurons in the primary visual cortex (V1) of awake macaque monkeys. Single- and multiple-unit recordings were made from V1 while the monkeys were performing a visual fixation task. The classical receptive field of each neuron was identified as a region responding to a spot stimulus. Neural responses were assessed using homogeneous surfaces at least three times as large as the receptive field as stimuli. We first examined the sensitivity of neurons to variation in local surface luminance, while the luminance of the surround was held constant. The activity of a large majority of surface-responsive neurons (106/115) varied monotonically with changes in surface luminance; in some the dynamic range was over 3 log units. This monotonic relation between surface luminance and neural activity was more evident later in the stimulus period than early on. The effect of the global luminance on neural activity was then assessed in 81 of the surface-responsive neurons by varying the luminance of the surround while holding the luminance of the surface constant. The activity of one group of neurons (25/81) was unaffected by the luminance of the surround; these neurons appear to encode the physical luminance of a surface covering the receptive field. The responses of the other neurons were affected by the luminance of the surround. The effects of the luminances of the surface and the surround on the activities of 26 of these neurons were in the same direction (either increased or decreased), while the effects on the remaining 25 neurons were in opposite directions. The activities of the latter group of neurons seemed to parallel the perceived brightness of the surface, whereas the former seemed to encode the level of illumination. There were differences across different types of neurons with regard to the layer distribution. These findings indicate that global luminance information significantly modulates the activity of surface-responsive V1 neurons and that not only physical luminance, but also perceived brightness, of a homogeneous surface is represented in V1.

Dynamic Properties of Recurrent Inhibition in Primary Visual Cortex: Contrast and Orientation Dependence of Contextual Effects

2000 ◽  
Vol 83 (2) ◽  
pp. 1019-1030 ◽  
Author(s):  
Valentin Dragoi ◽  
Mriganka Sur
Keyword(s):  
Visual Cortex ◽  
Receptive Field ◽  
Primary Visual Cortex ◽  
Dynamic Properties ◽  
Orientation Dependence ◽  
Recurrent Inhibition ◽  
Inhibitory Neurons ◽  
Classical Receptive Field ◽  
Contextual Interactions ◽  
Receptive Field Center

A fundamental feature of neural circuitry in the primary visual cortex (V1) is the existence of recurrent excitatory connections between spiny neurons, recurrent inhibitory connections between smooth neurons, and local connections between excitatory and inhibitory neurons. We modeled the dynamic behavior of intermixed excitatory and inhibitory populations of cells in V1 that receive input from the classical receptive field (the receptive field center) through feedforward thalamocortical afferents, as well as input from outside the classical receptive field (the receptive field surround) via long-range intracortical connections. A counterintuitive result is that the response of oriented cells can be facilitated beyond optimal levels when the surround stimulus is cross-oriented with respect to the center and suppressed when the surround stimulus is iso-oriented. This effect is primarily due to changes in recurrent inhibition within a local circuit. Cross-oriented surround stimulation leads to a reduction of presynaptic inhibition and a supraoptimal response, whereas iso-oriented surround stimulation has the opposite effect. This mechanism is used to explain the orientation and contrast dependence of contextual interactions in primary visual cortex: responses to a center stimulus can be both strongly suppressed and supraoptimally facilitated as a function of surround orientation, and these effects diminish as stimulus contrast decreases.

scholarly journals Homeostatic plasticity mechanisms in mouse V1

2017 ◽  
Vol 372 (1715) ◽  
pp. 20160504 ◽  
Author(s):  
Megumi Kaneko ◽  
Michael P. Stryker
Keyword(s):  
Visual Cortex ◽  
Primary Visual Cortex ◽  
Neuronal Activity ◽  
Dynamic Range ◽  
Ocular Dominance ◽  
Homeostatic Plasticity ◽  
Ocular Dominance Plasticity ◽  
The Brain

Mechanisms thought of as homeostatic must exist to maintain neuronal activity in the brain within the dynamic range in which neurons can signal. Several distinct mechanisms have been demonstrated experimentally. Three mechanisms that act to restore levels of activity in the primary visual cortex of mice after occlusion and restoration of vision in one eye, which give rise to the phenomenon of ocular dominance plasticity, are discussed. The existence of different mechanisms raises the issue of how these mechanisms operate together to converge on the same set points of activity. This article is part of the themed issue ‘Integrating Hebbian and homeostatic plasticity’.

Activation of metabotropic glutamate receptors has different effects in different layers of cat visual cortex

1997 ◽  
Vol 14 (1) ◽  
pp. 83-88 ◽  
Author(s):  
Silvia N.M. Reid ◽  
Nigel W. Daw
Keyword(s):  
Visual Cortex ◽  
Dicarboxylic Acid ◽  
Glutamate Receptors ◽  
Spontaneous Activity ◽  
Primary Visual Cortex ◽  
Metabotropic Glutamate Receptors ◽  
Visual Response ◽  
Single Neurons ◽  
Metabotropic Glutamate ◽  
Cat Visual Cortex

AbstractSingle neurons were recorded in cat primary visual cortex, and the effect of iontophoresis of the metabotropic glutamate agonist 1S,3R-aminocyclopentane-1.3-dicarboxylic acid (ACPD) was observed. In nearly all cases (41/43), ACPD reduced the visual response. In some cases ACPD also reduced spontaneous activity (24/43), and in other cases ACPD increased spontaneous activity (18/43). Increases were generally seen in infragranular layers (V and VI), and decreases in supragranular layers (II and III). The reduction in the visual response was also largest in supragranular layers. We conclude that activation of metabotropic glutamate receptors has both facilitatory and depressive effects in visual cortex, and the effect depends on the layer of the cell recorded.

>Checkerboard Visual Evoked Response in Evaluation and Management of Pituitary Tumors

Neurosurgery ◽  
1979 ◽  
Vol 5 (5) ◽  
pp. 553-558 ◽  
Author(s):  
Peggy S. Gott ◽  
Martin H. Weiss ◽  
Michael Apuzzo ◽  
Joseph P. Van Der Meulen
Keyword(s):  
Visual System ◽  
Pituitary Tumor ◽  
Visual Fields ◽  
Pattern Reversal ◽  
Checkerboard Pattern ◽  
Evoked Responses ◽  
Visual Evoked Response ◽  
Visual Evoked Responses ◽  
Suprasellar Extension ◽  
Visual Evoked

Abstract As a routine part of the evaluation of patients with pituitary tumor, visual evoked responses (VERs) to checkerboard pattern reversal were recorded from 83 patients with tomographically documented pituitary tumor. VER tests were correlated with examinations of visual acuity, color perception, and visual fields and with computerized tomographic scan evidence of suprasellar extension of the tumor. The purpose of the VER recording was to determine the presence of visual system compression by the tumor and thus contribute to the decision of whether surgery was necessary. Each of the patients who had suprasellar extension of the tumor sufficient to produce a visual field abnormality also had an abnormal VER. In addition, some patients with suprasellar extension had normal visual fields but abnormal visual evoked responses. Thus, the VER provided earlier evidence of suprasellar extension causing visual system compromise than did conventional visual tests.

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