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 Intact extrastriate visual network without primary visual cortex in a Rhesus macaque with naturally occurring Blindsight

2018 ◽  
Author(s):  
Holly Bridge ◽  
Andrew Bell ◽  
Matt Ainsworth ◽  
Jerome Sallet ◽  
Elsie Premereur ◽  
...  
Keyword(s):  
Visual Cortex ◽  
Rhesus Macaque ◽  
Primary Visual Cortex ◽  
Visual Stimulation ◽  
Brain Structures ◽  
Macaque Monkey ◽  
Full Field ◽  
Visual Cortical ◽  
And Control ◽  
Temporally Correlated

AbstractLesions of primate primary visual cortex (V1) lead to loss of conscious visual perception, and are often devastating to those affected. Understanding the neural consequences of such damage may aid the development of rehabilitation methods. In this rare case of a Rhesus macaque (monkey S), likely born without V1, we investigated the brain structures underlying residual visual abilities using multimodal magnetic resonance imaging. In-group behaviour was unremarkable. Compared to controls, visual structures outside of monkey S’s lesion appeared normal. Visual stimulation under anaesthesia with checkerboards activated lateral geniculate nucleus of monkey S, but not the pulvinar, while full-field moving dots activated the pulvinar. Functional connectivity analysis revealed a network of bilateral dorsal visual areas temporally correlated with V5/MT, consistent across lesion and control animals. Overall, we found an intact network of visual cortical areas even without V1, but little evidence for strengthened subcortical input to V5/MT supporting residual visual function.

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 Preserved extrastriate visual network in a monkey with substantial, naturally occurring damage to primary visual cortex

eLife ◽  
2019 ◽  
Vol 8 ◽  
Author(s):  
Holly Bridge ◽  
Andrew H Bell ◽  
Matthew Ainsworth ◽  
Jerome Sallet ◽  
Elsie Premereur ◽  
...  
Keyword(s):  
Visual Cortex ◽  
Primary Visual Cortex ◽  
Visual Stimulation ◽  
Macaque Monkey ◽  
Cortical Activation ◽  
Full Field ◽  
Task Training ◽  
Visual Cortical ◽  
And Control ◽  
Temporally Correlated

Lesions of primary visual cortex (V1) lead to loss of conscious visual perception with significant impact on human patients. Understanding the neural consequences of such damage may aid the development of rehabilitation methods. In this rare case of a Rhesus macaque (monkey S), likely born without V1, the animal’s in-group behaviour was unremarkable, but visual task training was impaired. With multi-modal magnetic resonance imaging, visual structures outside of the lesion appeared normal. Visual stimulation under anaesthesia with checkerboards activated lateral geniculate nucleus of monkey S, while full-field moving dots activated pulvinar. Visual cortical activation was sparse but included face patches. Consistently across lesion and control monkeys, functional connectivity analysis revealed an intact network of bilateral dorsal visual areas temporally correlated with V5/MT activation, even without V1. Despite robust subcortical responses to visual stimulation, we found little evidence for strengthened subcortical input to V5/MT supporting residual visual function or blindsight-like phenomena.

scholarly journals Peripheral sounds rapidly activate visual cortex: evidence from electrocorticography

2015 ◽  
Vol 114 (5) ◽  
pp. 3023-3028 ◽  
Author(s):  
David Brang ◽  
Vernon L. Towle ◽  
Satoru Suzuki ◽  
Steven A. Hillyard ◽  
Senneca Di Tusa ◽  
...  
Keyword(s):  
Visual Cortex ◽  
Primary Visual Cortex ◽  
Visual Stimulation ◽  
Specific Activity ◽  
Task Demands ◽  
Synaptic Activity ◽  
Visual Task ◽  
Depth Electrodes ◽  
Neurophysiological Studies ◽  
Visual Areas

Neurophysiological studies with animals suggest that sounds modulate activity in primary visual cortex in the presence of concurrent visual stimulation. Noninvasive neuroimaging studies in humans have similarly shown that sounds modulate activity in visual areas even in the absence of visual stimuli or visual task demands. However, the spatial and temporal limitations of these noninvasive methods prevent the determination of how rapidly sounds activate early visual cortex and what information about the sounds is relayed there. Using spatially and temporally precise measures of local synaptic activity acquired from depth electrodes in humans, we demonstrate that peripherally presented sounds evoke activity in the anterior portion of the contralateral, but not ipsilateral, calcarine sulcus within 28 ms of sound onset. These results suggest that auditory stimuli rapidly evoke spatially specific activity in visual cortex even in the absence of concurrent visual stimulation or visual task demands. This rapid auditory-evoked activation of primary visual cortex is likely to be mediated by subcortical pathways or direct cortical projections from auditory to visual areas.

scholarly journals A Quantitative Description of Short-Term Plasticity at Excitatory Synapses in Layer 2/3 of Rat Primary Visual Cortex

1997 ◽  
Vol 17 (20) ◽  
pp. 7926-7940 ◽  
Author(s):  
Juan A. Varela ◽  
Kamal Sen ◽  
Jay Gibson ◽  
Joshua Fost ◽  
L. F. Abbott ◽  
...  
Keyword(s):  
Visual Cortex ◽  
Primary Visual Cortex ◽  
Quantitative Description ◽  
Excitatory Synapses ◽  
Short Term ◽  
Short Term Plasticity ◽  
Layer 2

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 Tuning Properties of Genetically Identified Layer 2/3 Neuronal Types in the Primary Visual Cortex of Cre-Transgenic Mice

2011 ◽  
Vol 4 ◽  
Author(s):  
Hatim A. Zariwala ◽  
Linda Madisen ◽  
Kurt F. Ahrens ◽  
Amy Bernard ◽  
Edward S. Lein ◽  
...  
Keyword(s):  
Visual Cortex ◽  
Transgenic Mice ◽  
Primary Visual Cortex ◽  
Layer 2 ◽  
Neuronal Types

scholarly journals Orientation Tuning, But Not Direction Selectivity, Is Invariant to Temporal Frequency in Primary Visual Cortex

2005 ◽  
Vol 94 (2) ◽  
pp. 1336-1345 ◽  
Author(s):  
Bartlett D. Moore ◽  
Henry J. Alitto ◽  
W. Martin Usrey
Keyword(s):  
Visual Cortex ◽  
Primary Visual Cortex ◽  
Visual Stimulus ◽  
Visual Processing ◽  
Cortical Neurons ◽  
Temporal Frequency ◽  
Direction Selectivity ◽  
Orientation Tuning ◽  
Orientation Contrast ◽  
Wide Range

The activity of neurons in primary visual cortex is influenced by the orientation, contrast, and temporal frequency of a visual stimulus. This raises the question of how these stimulus properties interact to shape neuronal responses. While past studies have shown that the bandwidth of orientation tuning is invariant to stimulus contrast, the influence of temporal frequency on orientation-tuning bandwidth is unknown. Here, we investigate the influence of temporal frequency on orientation tuning and direction selectivity in area 17 of ferret visual cortex. For both simple cells and complex cells, measures of orientation-tuning bandwidth (half-width at half-maximum response) are ∼20–25° across a wide range of temporal frequencies. Thus cortical neurons display temporal-frequency invariant orientation tuning. In contrast, direction selectivity is typically reduced, and occasionally reverses, at nonpreferred temporal frequencies. These results show that the mechanisms contributing to the generation of orientation tuning and direction selectivity are differentially affected by the temporal frequency of a visual stimulus and support the notion that stability of orientation tuning is an important aspect of visual processing.

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