scholarly journals V1 receptive field structure contributes to neuronal response latency

2022 ◽  
Author(s):  
Amin Vafaei ◽  
Milad Mohammadi ◽  
Alireza Khadir ◽  
Erfan Zabeh ◽  
Faraz YazdaniBanafsheDaragh ◽  
...  
Keyword(s):  
Visual Cortex ◽  
Receptive Field ◽  
Response Latency ◽  
Neuronal Response ◽  
Underlying Mechanism ◽  
Geometrical Model ◽  
Fine Tuning ◽  
Neuronal Responses ◽  
Periodic Patterns ◽  
Response Latencies

The timing of neuronal responses is considered to be important for information transferring and communication across individual neurons. However, the sources of variabilities in the timing of neuronal responses are not well understood and sometimes over-interpreted. A systematic variability in the response latencies of the primary visual cortex has been reported in presence of drifting grating stimulus. Whereas the response latencies are systematically dependent on stimulus orientation. To understand the underlying mechanism of these systematic latencies, we recorded the neuronal response of the cat visual cortex, area 17, and simulated the response latency of V1 neurons, with two geometric models. We showed that outputs of these two models significantly predict the response latencies of the electrophysiology recording during orientation tasks. The periodic patterns created in the raster plots were dependent on the relative position of the stimulus rotation center and the receptive-field sub-regions. We argue the position of stimulus is contributing to systematic response latencies, dependent on drifting orientation. Therefore, we provide a toolbox based on our geometrical model for determining the exact location of RF sub-regions. Our result indicates that a major source of neuronal variability is the lack of fine-tuning in the task parameters. Considering the simplicity of the orientation selectivity task, we argue fine-tuning of stimulus properties is crucial for deduction of neural variability in higher-order cortical areas and understanding their neural dynamics.

scholarly journals Unifying Temporal Phenomena in Human Visual Cortex

2017 ◽  
Author(s):  
Jingyang Zhou ◽  
Noah C. Benson ◽  
Kendrick Kay ◽  
Jonathan Winawer
Keyword(s):  
Visual Cortex ◽  
Receptive Field ◽  
Temporal Dynamics ◽  
Gain Control ◽  
Spatial Vision ◽  
Research Area ◽  
Neuronal Responses ◽  
Stimulus Contrast ◽  
Temporal Properties ◽  
Cortical Responses

AbstractNeuronal responses in visual cortex show a diversity of complex temporal properties. These properties include sub-additive temporal summation, response reduction with repeated or sustained stimuli (adaptation), and slower dynamics at low stimulus contrast. Here, we hypothesize that these seemingly disparate effects can be explained by a single, shared computational mechanism. We propose a model consisting of a linear stage, followed by history-dependent gain control. The model accounts for these various temporal phenomena, tested against an unusually diverse set of measurements - intracranial electrodes in patients, fMRI, and macaque single unit spiking. The model further enables us to uncover a systematic and rich variety of temporal encoding strategies across visual cortex: First, temporal receptive field shape differs both across and within visual field maps. Second, later visual areas show more rapid and pronounced adaptation. Our study provides a new framework to understand the transformation between visual input and dynamical cortical responses.Author SummaryThe nervous system extracts meaning from the distribution of light over space and time. Spatial vision has been a highly successful research area, and the spatial receptive field has served as a fundamental and unifying concept that spans perception, computation, and physiology. While there has also been a large interest in temporal vision, the temporal domain has lagged the spatial domain in terms of quantitative models of how signals are transformed across the visual hierarchy. Here we present a model of temporal dynamics of neuronal responses in human cerebral cortex. We show that the model can accurately predict responses at the millisecond scale using intracortical electrodes in patient volunteers, and that the same model generalizes to multiple types of other measurements, including functional MRI and action potentials from monkey cortex. Further, we show that a single model can account for a variety of temporal phenomena, including short-term adaptation and slower dynamics at low stimulus contrast. By developing a computational model and showing that it successfully generalizes across measurement types, cortical areas, and stimuli, we provide new insights into how time-varying images are encoded and transformed into dynamic cortical responses.

Spatiotemporal characteristics of surround suppression in primary visual cortex and lateral geniculate nucleus of the cat

2014 ◽  
Vol 112 (3) ◽  
pp. 603-619 ◽  
Author(s):  
Satoshi Shimegi ◽  
Ayako Ishikawa ◽  
Hiroyuki Kida ◽  
Hiroshi Sakamoto ◽  
Sin-ichiro Hara ◽  
...  
Keyword(s):  
Visual Cortex ◽  
Receptive Field ◽  
Lateral Geniculate Nucleus ◽  
Primary Visual Cortex ◽  
Neuronal Response ◽  
High Specificity ◽  
Fast Component ◽  
Sinusoidal Grating ◽  
Temporal Properties ◽  
Lateral Geniculate

In the primary visual cortex (V1), a neuronal response to stimulation of the classical receptive field (CRF) is predominantly suppressed by a stimulus presented outside the CRF (extraclassical receptive field, ECRF), a phenomenon referred to as ECRF suppression. To elucidate the neuronal mechanisms and origin of ECRF suppression in V1 of anesthetized cats, we examined the temporal properties of the spatial extent and orientation specificity of ECRF suppression in V1 and the lateral geniculate nucleus (LGN), using stationary-flashed sinusoidal grating. In V1, we found three components of ECRF suppression: 1) local and fast, 2) global and fast, and 3) global and late. The local and fast component, which resulted from within 2° of the boundary of the CRF, started no more than 10 ms after the onset of the CRF response and exhibited low specificity for the orientation of the ECRF stimulus. These spatiotemporal properties corresponded to those of geniculate ECRF suppression, suggesting that the local and fast component of V1 is inherited from the LGN. In contrast, the two global components showed rather large spatial extents ∼5° from the CRF boundary and high specificity for orientation, suggesting that their possible origin is the cortex, not the LGN. Correspondingly, the local component was observed in all neurons of the thalamocortical recipient layer, while the global component was biased toward other layers. Therefore, we conclude that both subcortical and cortical mechanisms with different spatiotemporal properties are involved in ECRF suppression.

scholarly journals Physiological Correlates of Perceptual Learning in Monkey V1 and V2

2002 ◽  
Vol 87 (4) ◽  
pp. 1867-1888 ◽  
Author(s):  
Geoffrey M. Ghose ◽  
Tianming Yang ◽  
John H. R. Maunsell
Keyword(s):  
Visual Cortex ◽  
Receptive Field ◽  
Perceptual Learning ◽  
Neuronal Response ◽  
Orientation Discrimination ◽  
Visual Neurons ◽  
Receptive Field Properties ◽  
Visual Hemifield ◽  
Orientation Specificity ◽  
Behavioral Improvement

Performance in visual discrimination tasks improves with practice. Although the psychophysical parameters of these improvements have suggested the involvement of early areas in visual cortex, there has been little direct study of the physiological correlates of such perceptual learning at the level of individual neurons. To examine how neuronal response properties in the early visual system may change with practice, we trained monkeys for more than 6 mo in an orientation discrimination task in which behaviorally relevant stimuli were restricted to a particular retinal location and oriented around a specific orientation. During training the monkeys' discrimination thresholds gradually improved to much better than those of naive monkeys or humans. Although this improvement was specific to the trained orientation, it showed little retinotopic specificity. The receptive field properties of single neurons from regions representing the trained location and a location in the opposite visual hemifield were measured in V1 and V2. In most respects the receptive field properties in the representations of the trained and untrained regions were indistinguishable. However, in the regions of V1 and V2 representing the trained location, there were slightly fewer neurons whose optimal orientation was near the trained orientation. This resulted in a small but significant decrease in the V1 population response to the trained orientation at the trained location. Consequently, the observed neuronal populations did not exhibit any orientation-specific biases sufficient to explain the orientation specificity of the behavioral improvement. Pooling models suggest that the behavioral improvement was accomplished with a task-dependent and orientation-selective pooling of unaltered signals from early visual neurons. These data suggest that, even for training with stimuli suited to the selectivities found in early areas of visual cortex, behavioral improvements can occur in the absence of pronounced changes in the physiology of those areas.

FDG-PET Scanning Shows Distributed Changes in Cortical Activity Associated with Visual Hallucinations in Eye Disease

2019 ◽  
Vol 19 (1) ◽  
pp. 84-89 ◽  
Author(s):  
Lütfü Hanoglu ◽  
Sultan Yildiz ◽  
Tansel Cakir ◽  
Taha Hanoglu ◽  
Burak Yulug
Keyword(s):  
Visual Cortex ◽  
Fdg Pet ◽  
Underlying Mechanism ◽  
Posterior Cingulate Cortex ◽  
Eye Disease ◽  
Visual Hallucinations ◽  
Charles Bonnet Syndrome ◽  
Pet Scanning ◽  
Inferior Parietal Cortex ◽  
Visual Deafferentation

Background and Objective: Charles Bonnet Syndrome (CBS) has been defined as complex visual hallucinations (CVH) due to visual loss. The underlying mechanism of CBS is not clear and the underlying pathophysiology of the visual hallucinations in CBS patients and pure visually impaired patients is still not clear. </P><P> Methods: In our study, we have scanned three patients with eye disease and CBS (VH+) and three patients with eye disease without CBS (VH-) using FDG-PET. Results: Our results showed underactivity in the pons and overactivity in primary right left visual cortex and inferior parietal cortex in VH- patients and underactivity in left Broca, left inf frontal primary visual cortex and anterior and posterior cingulate cortex in VH+ patients relative to the normative 18FFDG PET data that was taken from the database consisting of 50 age-matched healthy adults without neuropsychiatric disorders. Conclusion: From this distributed pattern of activity changes, we conclude that the generation of visual hallucination in CBS is associated with bottom-up and top-down mechanism rather than the generally accepted visual deafferentation-related hyperexcitability theory.

scholarly journals A9 DORSAL ROOT GANGLIA NEURONAL RESPONSES AND SUBSTANCE P PRODUCTION ARE HIGHER IN MALE MICE

2021 ◽  
Vol 4 (Supplement_1) ◽  
pp. 10-11
Author(s):  
J Pujo ◽  
G De Palma ◽  
J Lu ◽  
S M Collins ◽  
P Bercik
Keyword(s):  
Abdominal Pain ◽  
Substance P ◽  
Gut Microbiota ◽  
Sensory Neurons ◽  
Dorsal Root ◽  
Neuronal Response ◽  
Neuronal Responses ◽  
Visceral Sensitivity ◽  
Germ Free

Abstract Background Abdominal pain is a common complaint in patients with chronic gastrointestinal disorders. Accumulating evidence suggests that gut microbiota is an important determinant of gut function, including visceral sensitivity. Germ-free (GF) mice have been shown to display visceral hypersensitivity, which normalizes after colonization. Sex also appears to play a key role in visceral sensitivity, as women report more abdominal pain than men. Thus, both gut bacteria and sex are important in the regulation of gut nociception, but the underlying mechanisms remain poorly understood. Aims To investigate the role of gut microbiota and sex in abdominal pain. Methods We used primary cultures of sensory neurons from dorsal root ganglia (DRG) of female and male conventionally raised (SPF) or germ-free (GF) mice (7–18 weeks old). To study the visceral afferent activity in vitro, calcium mobilization in DRG sensory neurons was measured by inverted fluorescence microscope using a fluorescent calcium probe Fluo-4 (1mM). Two parameters were considered i) the percentage of responding neurons ii) the intensity of the neuronal response. First, DRG sensory neurons were stimulated by a TRPV1 agonist capsaicin (12.5nM, 125nM and 1.25µM) or by a mixture of G-protein coupled receptors agonist (GPCR: bradykinin, histamine and serotonin; 1µM, 10µM and 100µM). We next measured the neuronal production of substance P and calcitonin gene-related peptide (CGRP), two neuropeptides associated with nociception, in response to capsaicin (1.25µM) or GPCR agonists (100µM) by ELISA and EIA, respectively. Results The percentage of neurons responding to capsaicin and GPCR agonists was similar in male and female SPF and GF mice. However, the intensity of the neuronal response was higher in SPF male compared to SPF female in response to capsaicin (125nM: p=0.0336; 1.25µM: p=0.033) but not to GPCR agonists. Neuronal activation was similar in GF and SPF mice of both sexes after administration of capsaicin or GPCR agonists. Furthermore, substance P and CGRP production by sensory neurons induced by capsaicin or GPCR agonists was similar in SPF and GF mice, regardless of sex. However, while the response to capsaicin was similar, the GPCR agonists-induced production of substance P was higher in SPF male mice compared to SPF females (p=0.003). The GPCR agonists-induced production of CGRP was similar in SPF male and female mice. Conclusions Our data suggest that at the level of DRG neurons, the absence of gut microbiota does not predispose to visceral hypersensitivity. The intensity of DRG neuronal responses to capsaicin and the GPCR agonists-induced production of substance P are higher in male compared to female mice, in contrast to previously published studies in various models of acute and chronic pain. Further studies are thus needed to investigate the role of sex in visceral sensitivity. Funding Agencies CIHR

scholarly journals Prediction of Orientation Selectivity from Receptive Field Architecture in Simple Cells of Cat Visual Cortex

Neuron ◽  
2001 ◽  
Vol 30 (1) ◽  
pp. 263-274 ◽  
Author(s):  
Ilan Lampl ◽  
Jeffrey S. Anderson ◽  
Deda C. Gillespie ◽  
David Ferster
Keyword(s):  
Visual Cortex ◽  
Receptive Field ◽  
Orientation Selectivity ◽  
Simple Cells ◽  
Cat Visual Cortex
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