The role of ipsilateral and contralateral inputs from primary cortex in responses of area 21a neurons in cats

1994 ◽  
Vol 11 (5) ◽  
pp. 839-849 ◽  
Author(s):  
A. Michalski ◽  
B. M. Wimborne ◽  
G. H. Henry
Keyword(s):  
Visual Cortex ◽  
Primary Visual Cortex ◽  
Tuning Curve ◽  
Excitatory Input ◽  
Direction Selectivity ◽  
Orientation Tuning ◽  
Inhibitory Input ◽  
Area 21A ◽  
Areas 17 And 18 ◽  
Orientation Specificity

AbstractNeuronal responses in cat visual area 21a were analyzed when the primary visual cortex (areas 17 and 18) was deactivated by cooling. Ipsilateral and contralateral cortices were deactivated separately. Results established that (1) cooling the ipsilateral primary cortex diminished the activity of all area 21a cells and, in 30%, blocked responsiveness altogether, and (2) cooling the contralateral primary cortex initially increased activity in area 21a cells but, with further cooling, reduced it to below the original level although only 9% of cells ceased responding. These findings were then compared to earlier results in which bilateral deactivation of the primary cortex greatly reduced and, in most cases, blocked the activity of area 21a cells (Michalski et al., 1993). Despite the response attenuation following cooling of the primary visual cortex (either ipsilateral or contralateral), neurons of area 21a retained their original orientation specificity and sharpness of tuning (measured as the half-width at half-height of the orientation tuning curve). Direction selectivity also tended to remain unchanged. We concluded that for area 21a cells (1) the ipsilateral primary cortex provides the main excitatory input; (2) the contralateral primary cortex supplies a large inhibitory input; and (3) the nature of orientation specificity, sharpness of orientation tuning, and direction selectivity are largely unaffected by removal of the ipsilateral hemisphere excitatory input or the contralateral hemisphere inhibitory input.

scholarly journals Temporo-nasally biased moving grating selectivity in mouse primary visual cortex

2019 ◽  
Author(s):  
Marie Tolkiehn ◽  
Simon R. Schultz
Keyword(s):  
Visual Cortex ◽  
Spatial Frequency ◽  
Primary Visual Cortex ◽  
Moving Objects ◽  
Direction Selectivity ◽  
Orientation Tuning ◽  
High Signal ◽  
Forward Movement ◽  
Upward Moving

AbstractOrientation tuning in mouse primary visual cortex (V1) has long been reported to have a random or “salt-and-pepper” organisation, lacking the structure found in cats and primates. Laminar in-vivo multi-electrode array recordings here reveal previously elusive structure in the representation of visual patterns in the mouse visual cortex, with temporo-nasally drifting gratings eliciting consistently highest neuronal responses across cortical layers and columns, whilst upward moving gratings reliably evoked the lowest activities. We suggest this bias in direction selectivity to be behaviourally relevant as objects moving into the visual field from the side or behind may pose a predatory threat to the mouse whereas upward moving objects do not. We found furthermore that direction preference and selectivity was affected by stimulus spatial frequency, and that spatial and directional tuning curves showed high signal correlations decreasing with distance between recording sites. In addition, we show that despite this bias in direction selectivity, it is possible to decode stimulus identity and that spatiotemporal features achieve higher accuracy in the decoding task whereas spike count or population counts are sufficient to decode spatial frequencies implying different encoding strategies.Significance statementWe show that temporo-nasally drifting gratings (i.e. opposite the normal visual flow during forward movement) reliably elicit the highest neural activity in mouse primary visual cortex, whereas upward moving gratings reliably evoke the lowest responses. This encoding may be highly behaviourally relevant, as objects approaching from the periphery may pose a threat (e.g. predators), whereas upward moving objects do not. This is a result at odds with the belief that mouse primary visual cortex is randomly organised. Further to this biased representation, we show that direction tuning depends on the underlying spatial frequency and that tuning preference is spatially correlated both across layers and columns and decreases with cortical distance, providing evidence for structural organisation in mouse primary visual cortex.

Relationship between input connectivity, morphology and orientation tuning of layer 2/3 pyramidal cells in mouse visual cortex

2020 ◽  
Author(s):  
Simon Weiler ◽  
Drago Guggiana Nilo ◽  
Tobias Bonhoeffer ◽  
Mark Hübener ◽  
Tobias Rose ◽  
...  
Keyword(s):  
Visual Cortex ◽  
Synaptic Input ◽  
Pyramidal Cells ◽  
Excitatory Input ◽  
Orientation Tuning ◽  
Inhibitory Input ◽  
Layer 2 ◽  
Dendritic Complexity ◽  
Inhibitory Synaptic Input

AbstractNeocortical pyramidal cells (PCs) display functional specializations defined by their excitatory and inhibitory circuit connectivity. For layer 2/3 (L2/3) PCs, little is known about the detailed relationship between their neuronal response properties, dendritic structure and their underlying circuit connectivity at the level of single cells. Here, we ask whether L2/3 PCs in mouse primary visual cortex (V1) differ in their functional intra- and interlaminar connectivity patterns, and how this relates to differences in visual response properties. Using a combined approach, we first characterized the orientation and direction tuning of individual L2/3 PCs with in vivo 2-photon calcium imaging. Subsequently, we performed excitatory and inhibitory synaptic input mapping of the same L2/3 PCs in brain slices using laser scanning photostimulation (LSPS).Our data from this structure-connectivity-function analysis show that the sources of excitatory and inhibitory synaptic input are different in their laminar origin and horizontal location with respect to cell position: On average, L2/3 PCs receive more inhibition than excitation from within L2/3, whereas excitation dominates input from L4 and L5. Horizontally, inhibitory input originates from locations closer to the horizontal position of the soma, while excitatory input arises from more distant locations in L4 and L5. In L2/3, the excitatory and inhibitory inputs spatially overlap on average. Importantly, at the level of individual neurons, PCs receive inputs from presynaptic cells located spatially offset, vertically and horizontally, relative to the soma. These input offsets show a systematic correlation with the preferred orientation of the postsynaptic L2/3 PC in vivo. Unexpectedly, this correlation is higher for inhibitory input offsets within L2/3 than for excitatory input offsets. When relating the dendritic complexity of L2/3 PCs to their orientation tuning, we find that sharply tuned cells have a less complex apical tree compared to broadly tuned cells. These results indicate that the spatial input offsets of the functional input connectivity are linked to orientation preference, while the orientation selectivity of L2/3 PCs is more related to the dendritic complexity.

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.

scholarly journals Traumatic brain injury to primary visual cortex produces long-lasting circuit dysfunction

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Jan C. Frankowski ◽  
Andrzej T. Foik ◽  
Alexa Tierno ◽  
Jiana R. Machhor ◽  
David C. Lyon ◽  
...  
Keyword(s):  
Traumatic Brain Injury ◽  
Visual Cortex ◽  
Brain Injury ◽  
Primary Visual Cortex ◽  
Visual Stimuli ◽  
Orientation Tuning ◽  
V1 Neurons ◽  
Adult Mice ◽  
Electrophysiological Recordings

AbstractPrimary sensory areas of the mammalian neocortex have a remarkable degree of plasticity, allowing neural circuits to adapt to dynamic environments. However, little is known about the effects of traumatic brain injury on visual circuit function. Here we used anatomy and in vivo electrophysiological recordings in adult mice to quantify neuron responses to visual stimuli two weeks and three months after mild controlled cortical impact injury to primary visual cortex (V1). We found that, although V1 remained largely intact in brain-injured mice, there was ~35% reduction in the number of neurons that affected inhibitory cells more broadly than excitatory neurons. V1 neurons showed dramatically reduced activity, impaired responses to visual stimuli and weaker size selectivity and orientation tuning in vivo. Our results show a single, mild contusion injury produces profound and long-lasting impairments in the way V1 neurons encode visual input. These findings provide initial insight into cortical circuit dysfunction following central visual system neurotrauma.

Processing of form and motion in area 21a of cat visual cortex

1993 ◽  
Vol 10 (1) ◽  
pp. 93-115 ◽  
Author(s):  
B. Dreher ◽  
A. Michalski ◽  
R. H. T. Ho ◽  
C. W. F. Lee ◽  
W. Burke
Keyword(s):  
Spatial Organization ◽  
Receptive Fields ◽  
Direction Selectivity ◽  
Orientation Tuning ◽  
Area 17 ◽  
Horizontal Strip ◽  
Tuning Curves ◽  
Mean Width ◽  
Area 21A ◽  
The Mean

AbstractExtracellular recordings from single neurons have been made from presumed area 21a of the cerebral cortex of the cat, anesthetized with N2O/O2/sodium pentobarbitone mixture. Area 21a contains mainly a representation of a central horizontal strip of contralateral visual field about 5 deg above and below the horizontal meridian.Excitatory discharge fields of area 21a neurons were substantially (or slightly but significantly) larger than those of neurons at corresponding eccentricities in areas 17, 19, or 18, respectively. About 95% of area 21a neurons could be activated through either eye and the input from the ipsilateral eye was commonly dominant. Over 90% and less than 10% of neurons had, respectively, C-type and S-type receptive-field organization. Virtually all neurons were orientation-selective and the mean width at half-height of the orientation tuning curves at 52.9 deg was not significantly different from that of neurons in areas 17 and 18. About 30% of area 21a neurons had preferred orientations within 15 deg of the vertical.The mean direction-selectivity index (32.8%) of area 21a neurons was substantially lower than the indices for neurons in areas 17 or 18. Only a few neurons exhibited moderately strong end-zone inhibition. Area 21a neurons responded poorly to fast-moving stimuli and the mean preferred velocity at about 12.5 deg/s was not significantly different from that for area 17 neurons.Selective pressure block of Y fibers in contralateral optic nerve resulted in a small but significant reduction in the preferred velocities of neurons activated via the Y-blocked eye. By contrast, removal of the Y input did not produce significant changes in the spatial organization of receptive fields (S or C type), the size of the discharge fields, the width of orientation tuning curves, or direction-selectivity indices.Our results are consistent with the idea that area 21a receives its principal excitatory input from area 17 and is involved mainly in form rather than motion analysis.

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.

Heterogeneity in local distributions of orientation-selective neurons in the cat primary visual cortex

1996 ◽  
Vol 13 (3) ◽  
pp. 509-516 ◽  
Author(s):  
Pedro E. Maldonado ◽  
Charles M. Gray
Keyword(s):  
Visual Cortex ◽  
Primary Visual Cortex ◽  
Local Level ◽  
Spike Trains ◽  
Preferred Orientation ◽  
Orientation Tuning ◽  
Area 17 ◽  
Average Difference ◽  
Orientation Preference ◽  
Neuronal Spike Trains

AbstractWe have employed the tetrode technique, which allows accurate discrimination of individual neuronal spike trains from multiunit recordings, in order to examine the variation of orientation selectivity among local groups of neurons. We recorded a total of 321 cells from 62 sites in area 17 of halothane-anesthetized cats; each site contained between three to ten neurons that were estimated to be less than 65 μm away from the tetrode tip. For each cell, we determined the orientation tuning in response to moving bars. Of the cells tested, 8.4% were unresponsive, 22.7% had no preferential response to any particular orientation, while 68.8% were tuned. The average difference in preferred orientation between cell pairs recorded at the same site was 10.7 deg, but the variance in preferred orientation differences differed significantly among sites. Some clusters of cells exhibited the same or nearly the same orientation preference, while others had orientation preferences that differed by as much as 90 deg. Our data demonstrate that the tuning for orientation is more heterogeneously distributed at a local level than previous studies have suggested.

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