scholarly journals Regulation of expression site and generalizability of experience-dependent plasticity in visual cortex

2019 ◽  
Author(s):  
Crystal L. Lantz ◽  
Sachiko Murase ◽  
Elizabeth M. Quinlan
Keyword(s):  
Visual Cortex ◽  
Primary Visual Cortex ◽  
Visual Stimulus ◽  
High Frequency ◽  
Visual Stimulation ◽  
Visual Stimuli ◽  
Low Frequency ◽  
Visual Response ◽  
Dependent Plasticity ◽  
Primary Mouse

SummaryThe experience-dependent decrease in stimulus detection thresholds that underly perceptual learning can be induced by repetitive exposure to a visual stimulus. Robust stimulus-selective potentiation of visual responses is induced in the primary mouse visual cortex by repetitive low frequency visual stimulation (LFVS). How the parameters of the repetitive visual stimulus impact the site and specificity of this experience-dependent plasticity is currently a subject of debate. Here we demonstrate that the stimulus selective response potentiation induced by repetitive low frequency (1 Hz) stimulation, which is typically limited to layer 4, shifts to superficial layers following manipulations that enhance plasticity in primary visual cortex. In contrast, repetitive high frequency (10 Hz) visual stimulation induces response potentiation that is expressed in layers 4 and 5/6, and generalizes to novel visual stimuli. Repetitive visual stimulation also induces changes in the magnitude and distribution of oscillatory activity in primary visual cortex, however changes in oscillatory power do not predict the locus or specificity of response potentiation. Instead we find that robust response potentiation is induced by visual stimulation that resets the phase of ongoing gamma oscillations. Furthermore, high frequency, but not low frequency, repetitive visual stimulation entrains oscillatory rhythms with enhanced sensitivity to phase reset, such that familiar and novel visual stimuli induce similar visual response potentiation.

scholarly journals Pure tones modulate the representation of orientation and direction in the primary visual cortex

2019 ◽  
Vol 121 (6) ◽  
pp. 2202-2214 ◽  
Author(s):  
John P. McClure ◽  
Pierre-Olivier Polack
Keyword(s):  
Visual Cortex ◽  
Primary Visual Cortex ◽  
Visual Stimulus ◽  
Visual Stimuli ◽  
Direction Selectivity ◽  
Multimodal Integration ◽  
Visual Responses ◽  
V1 Neurons ◽  
Pure Tones ◽  
The Impact

Multimodal sensory integration facilitates the generation of a unified and coherent perception of the environment. It is now well established that unimodal sensory perceptions, such as vision, are improved in multisensory contexts. Whereas multimodal integration is primarily performed by dedicated multisensory brain regions such as the association cortices or the superior colliculus, recent studies have shown that multisensory interactions also occur in primary sensory cortices. In particular, sounds were shown to modulate the responses of neurons located in layers 2/3 (L2/3) of the mouse primary visual cortex (V1). Yet, the net effect of sound modulation at the V1 population level remained unclear. In the present study, we performed two-photon calcium imaging in awake mice to compare the representation of the orientation and the direction of drifting gratings by V1 L2/3 neurons in unimodal (visual only) or multimodal (audiovisual) conditions. We found that sound modulation depended on the tuning properties (orientation and direction selectivity) and response amplitudes of V1 L2/3 neurons. Sounds potentiated the responses of neurons that were highly tuned to the cue’s orientation and direction but weakly active in the unimodal context, following the principle of inverse effectiveness of multimodal integration. Moreover, sound suppressed the responses of neurons untuned for the orientation and/or the direction of the visual cue. Altogether, sound modulation improved the representation of the orientation and direction of the visual stimulus in V1 L2/3. Namely, visual stimuli presented with auditory stimuli recruited a neuronal population better tuned to the visual stimulus orientation and direction than when presented alone. NEW & NOTEWORTHY The primary visual cortex (V1) receives direct inputs from the primary auditory cortex. Yet, the impact of sounds on visual processing in V1 remains controverted. We show that the modulation by pure tones of V1 visual responses depends on the orientation selectivity, direction selectivity, and response amplitudes of V1 neurons. Hence, audiovisual stimuli recruit a population of V1 neurons better tuned to the orientation and direction of the visual stimulus than unimodal visual stimuli.

scholarly journals Visual recognition is heralded by shifts in local field potential oscillations and inhibitory networks in primary visual cortex

2020 ◽  
Author(s):  
Dustin J. Hayden ◽  
Daniel P. Montgomery ◽  
Samuel F. Cooke ◽  
Mark F. Bear
Keyword(s):  
Visual Cortex ◽  
Primary Visual Cortex ◽  
Local Field ◽  
High Frequency ◽  
Peak Power ◽  
Field Potential ◽  
Low Frequency ◽  
Inhibitory Neurons ◽  
Stimulus Familiarity ◽  
Frequency Power

AbstractFiltering out familiar, irrelevant stimuli eases the computational burden on the cerebral cortex. Inhibition is a candidate mechanism in this filtration process. Oscillations in the cortical local field potential (LFP) serve as markers of the engagement of different inhibitory neurons. In awake mice, we find pronounced changes in LFP oscillatory activity present in layer 4 of primary visual cortex (V1) with progressive stimulus familiarity. Over days of repeated stimulus presentation, low frequency (alpha/beta ~15 Hz peak) power increases while high frequency (gamma ~65 Hz peak) power decreases. This high frequency activity re-emerges when a novel stimulus is shown. Thus, high frequency power is a marker of novelty while low frequency power signifies familiarity. Two-photon imaging of neuronal activity reveals that parvalbumin-expressing inhibitory neurons disengage with familiar stimuli and reactivate to novelty, consistent with their known role in gamma oscillations, whereas somatostatin-expressing inhibitory neurons show opposing activity patterns, indicating a contribution to the emergence of lower frequency oscillations. We also reveal that stimulus familiarity and novelty have differential effects on oscillations and cell activity over a shorter timescale of seconds. Taken together with previous findings, we propose a model in which two interneuron circuits compete to drive familiarity or novelty encoding.

scholarly journals Sound improves neuronal encoding of visual stimuli in mouse primary visual cortex

2021 ◽  
Author(s):  
Aaron M. Williams ◽  
Christopher F. Angeloni ◽  
Maria Neimark Geffen
Keyword(s):  
Visual Cortex ◽  
Primary Visual Cortex ◽  
Neuronal Activity ◽  
Visual Stimulus ◽  
Visual Stimuli ◽  
Audiovisual Integration ◽  
Neuronal Firing ◽  
Auditory Information ◽  
Visual Responses ◽  
Neuronal Encoding

In everyday life, we integrate visual and auditory information in routine tasks such as navigation and communication. While it is known that concurrent sound can improve visual perception, the neuronal correlates of this audiovisual integration are not fully understood. Specifically, it remains unknown whether improvement of the detection and discriminability of visual stimuli due to sound is reflected in the neuronal firing patterns in the primary visual cortex (V1). Furthermore, presentation of the sound can induce movement in the subject, but little is understood about whether and how sound-induced movement contributes to V1 neuronal activity. Here, we investigated how sound and movement interact to modulate V1 visual responses in awake, head-fixed mice and whether this interaction improves neuronal encoding of the visual stimulus. We presented visual drifting gratings with and without simultaneous auditory white noise to awake mice while recording mouse movement and V1 neuronal activity. Sound modulated the light-evoked activity of 80% of light-responsive neurons, with 95% of neurons exhibiting increased activity when the auditory stimulus was present. Sound consistently induced movement. However, a generalized linear model revealed that sound and movement had distinct and complementary effects of the neuronal visual responses. Furthermore, decoding of the visual stimulus from the neuronal activity was improved with sound, an effect that persisted even when controlling for movement. These results demonstrate that sound and movement modulate visual responses in complementary ways, resulting in improved neuronal representation of the visual stimulus. This study clarifies the role of movement as a potential confound in neuronal audiovisual responses, and expands our knowledge of how multi-modal processing is mediated at a neuronal level in the awake brain.

scholarly journals Alternating Periods of High and Low-Entropy Neural Ensemble Activity During Image Processing in the Primary Visual Cortex of Rats

2016 ◽  
Vol 10 (1) ◽  
pp. 51-61
Author(s):  
Xiaoyuan Li ◽  
Qiwei Li ◽  
Li Shi ◽  
Liucheng Jiao
Keyword(s):  
Visual Cortex ◽  
Primary Visual Cortex ◽  
Visual Processing ◽  
Visual Stimulation ◽  
Visual Stimuli ◽  
Field Potential ◽  
Discrete Wavelet ◽  
Neural Ensemble ◽  
Highly Nonlinear ◽  
Ensemble Activity

The response properties of individual neurons in the primary visual cortex (V1) are among the most thoroughly described in the mammalian central nervous system, but they reveal less about higher-order processes like visual perception. Neural activity is highly nonlinear and non-stationary over time, greatly complicating the relationships among the spatiotemporal characteristics of visual stimuli, local field potential (LFP) signal components, and the underlying neuronal activity patterns. We applied discrete wavelet transformation to detect new features of the LFP that may better describe the association between visual input and neural ensemble activity. The relative wavelet energy (RWE), wavelet entropy (WS), and the mean WS were computed from LFPs recorded in rat V1 during three distinct visual stimuli: low ambient light, a uniform grey computer screen, and simple pictures of common scenes. The time evolution of the RWE within the γ band (31-62.5 Hz) was the dominant component over certain periods during visual stimulation. Mean WS decreased with increasing complexity of the visual image, and the time-dependent WS alternated between periods of highly ordered and disordered population activity. In conclusion, these alternating periods of high and low WS may correspond to different aspects of visual processing, such as feature extraction and perception.

scholarly journals The output of interneurons in the primary visual cortex is best reflected by pre-synaptic activity, not somatic activity

2021 ◽  
Author(s):  
Rozan Vroman ◽  
Lawrie S McKay
Keyword(s):  
Visual Cortex ◽  
Primary Visual Cortex ◽  
Visual Stimulus ◽  
Visual Stimulation ◽  
Time Windows ◽  
Synaptic Activity ◽  
Excitatory Effect ◽  
Full Field ◽  
Layer 2 ◽  
Initial Onset

Recent advances in 2-photon calcium-imaging in awake mice have made it possible to study the effect of different behavioural states on cortical circuitry. Many studies assume that somatic activity can be used as a measure for neuronal output. We set out to test the validity of this assumption by comparing somatic activity with the pre-synaptic activity of VIP (Vasoactive intestinal peptide)- and SST (Somatostatin)-positive interneurons in layer 2/3 of the primary visual cortex (V1). We used mice expressing genetically encoded calcium indicators in VIP/SST-interneurons across the whole cell (VIP/SST:GCaMP6f) or confined to pre-synapses (VIP/SST:SyGCaMP5). Mice were exposed to a full-field visual stimulation protocol consisting of 60-second-long presentations of moving Gabor gratings (0.04 cpd, 2 Hz) alternated by 30 seconds of grey screen. During imaging, mice were placed on an air-suspended Styrofoam ball, allowing them to run voluntarily. We compared neural activity during three 4-second time-windows: Before visual stimulation (−4 to 0 sec), during the initial onset (1 to 5 sec) and at the end of the stimulation (56 to 60 sec.). These were further compared while the mice were stationary and while they were voluntarily locomoting. Unlike VIP-somas, VIP-pre-synapses showed strong suppressive responses to the visual stimulus. Furthermore, VIP-somas were positively correlated with locomotion, whereas in VIP-synapses we observed a split between positive and negative correlations. In addition, a similar but weaker distinction was found between SST-somas and pre-synapses. The excitatory effect of locomotion in VIP-somas increased over the course of the visual stimulus but this property was only shared with the positively correlated VIP-pre-synapses. The remaining negatively correlated pre-synapses showed no relation to the overall activity of the Soma. Our results suggest that when making statements about the involvement of interneurons in V1 layer 2/3 circuitry it is crucial to measure from synaptic terminals as well as from somas.

scholarly journals Sustained High- and Low-Frequency Neural Responses to Visual Stimuli in Scalp EEG

2018 ◽  
Author(s):  
Edden M. Gerber ◽  
Leon Y. Deouell
Keyword(s):  
Visual Cortex ◽  
Visual Field ◽  
Visual Processing ◽  
High Frequency ◽  
Visual Stimuli ◽  
Low Frequency ◽  
Right Visual Field ◽  
Visual Responses ◽  
Scalp Eeg ◽  
Sustained Responses

AbstractWhat are the neurophysiological correlates of sustained visual processing in the scalp EEG signal? In a previous study using intracranial recordings in humans, we found that presentation of visual stimuli for prolonged durations (up to 1.5 seconds) was associated with two kinds of sustained neural activity patterns: a high-frequency broadband (>30 Hz) response that tracked the duration of the stimulus with high precision in early visual cortex (EVC), and with lesser temporal precision in downstream category-selective areas; and a sustained low-frequency potential shift appearing in a small subset of EVC sites. Using a similar approach of presenting images for variable durations to identify sustained activity, we provide the first comprehensive characterization of the manifestation of sustained visual responses as recorded with EEG. In a series of four experiments, we found that both high- and low-frequency sustained responses can be detected on the scalp. The high frequency activity could be detected with high signal to noise ratio only in a subset of individual subjects, in whom it was unequivocal and highly localized. The low frequency sustained response was sensitive to the size and position of the stimulus in the visual field. Both response types showed strong lateralization for stimuli on the left vs. right visual field, suggesting a retinotopic visual cortical source. However, different scalp topographies and different modulation by stimulus properties suggest that the two types of sustained responses are likely driven by distinct sources, and reflect different aspects of sustained processing in the visual cortex.

Effect of passive eye position changes on retinogeniculate transmission in the cat

1990 ◽  
Vol 63 (3) ◽  
pp. 502-522 ◽  
Author(s):  
R. Lal ◽  
M. J. Friedlander
Keyword(s):  
Firing Rate ◽  
Action Potentials ◽  
Visual Stimulation ◽  
Visual Stimuli ◽  
Eye Position ◽  
Visual Response ◽  
Nonlinear Gain ◽  
Physiological Tests ◽  
Normalized Gain ◽  
Stimulation Of

1. Extracellular recordings were made from single neurons in layer A of the left dorsal lateral geniculate nucleus (LGNd) of anesthetized and paralyzed adult cats. Responses to retinotopically identical visual stimuli (presented through the right eye) were recorded at several positions of the left eye in its orbit. Visual stimuli consisted of drifting sinusoidal gratings of optimal temporal and spatial frequencies at twice threshold contrast. Visual stimulation of the left eye was blocked by a variety of methods, including intravitreal injection of tetrodotoxin (TTX). The change in position of the left eye was achieved by passive movements in a randomized and interleaved fashion. Of 237 neurons studied, responses were obtained from 143 neurons on 20-100 trials of identical visual stimulation at each of six eye positions. Neurons were classified as X- or Y- on the basis of a standard battery of physiological tests (primarily linearity of spatial summation and response latency to electrical stimulation of the optic chiasm). 2. The effect of eye position on the visual response of the 143 neurons was analyzed with respect to the number of action potentials elicited and the peak firing rate. Fifty-seven (40%) neurons had a significant effect [by one-factor repeated-measure analysis of variance (ANOVA), P less than 0.05] of eye position on the visual response by either criterion (number of action potentials or peak firing rate). Of these 57 neurons, 47 had a significant effect (P less than 0.05) with respect to the number of action potentials and 23 had a significant effect (P less than 0.05) by both criteria. Thus the permissive measure by either criterion and the conservative measure by both criteria resulted in 40% and 16%, respectively, of all neurons' visual responses being significantly affected by eye position. 3. For the 47 neurons with a significant effect of eye position (number of action potentials criterion), a trend analysis of eye position versus visual response showed a linear trend (P less than 0.05) for 9 neurons, a quadratic trend (P less than 0.05) for 32 neurons, and no significant trend for the 6 remaining neurons. The trends were approximated with linear and nonlinear gain fields (range of eye position change over which the visual response was modulated). The gain fields of individual neurons were compared by measuring the normalized gain (change in neuronal response per degree change of eye position). The mean normalized gain for the 47 neurons was 4.3. 4. The nonlinear gain fields were generally symmetric with respect to nasal versus temporal changes in eye position.(ABSTRACT TRUNCATED AT 400 WORDS)

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