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

2019 ◽  
Author(s):  
Marie Tolkiehn ◽  
Simon R. Schultz

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.

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Jan C. Frankowski ◽  
Andrzej T. Foik ◽  
Alexa Tierno ◽  
Jiana R. Machhor ◽  
David C. Lyon ◽  
...  

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.


2005 ◽  
Vol 94 (2) ◽  
pp. 1336-1345 ◽  
Author(s):  
Bartlett D. Moore ◽  
Henry J. Alitto ◽  
W. Martin Usrey

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.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Mineki Oguchi ◽  
Jiang Jiasen ◽  
Toshihide W. Yoshioka ◽  
Yasuhiro R. Tanaka ◽  
Kenichi Inoue ◽  
...  

AbstractIn vivo calcium imaging with genetically encoded indicators has recently been applied to macaque brains to monitor neural activities from a large population of cells simultaneously. Microendoscopic calcium imaging combined with implantable gradient index lenses captures neural activities from deep brain areas with a compact and convenient setup; however, this has been limited to rodents and marmosets. Here, we developed miniature fluorescent microscopy to image neural activities from the primary visual cortex of behaving macaques. We found tens of clear fluorescent signals from three of the six brain hemispheres. A subset of these neurons showed clear retinotopy and orientation tuning. Moreover, we successfully decoded the stimulus orientation and tracked the cells across days. These results indicate that microendoscopic calcium imaging is feasible and reasonable for investigating neural circuits in the macaque brain by monitoring fluorescent signals from a large number of neurons.


2018 ◽  
Author(s):  
Rylan Scott Larsen ◽  
Emily Turschak ◽  
Tanya Daigle ◽  
Hongkui Zeng ◽  
Jun Zhuang ◽  
...  

Neuromodulators such as acetylcholine, noradrenaline (norepinephrine), and serotonin are released into the cortex by axons ascending from subcortical nuclei. These neuromodulators have been hypothesized to influence cortical function during behavioral periods such as arousal, locomotion, exploration, and attention. To determine when these neuromodulatory projections were active, we expressed the genetically-encoded calcium sensor GCaMP6 in neuromodulatory axons which project to the mouse primary visual cortex and performed two-photon microscopy to monitor their activity in vivo. We observed that the fluorescence of both cholinergic and noradrenergic axons increased during periods of pupil dilation, with the fluorescence of the axons rising less than one second before eye pupil dilation. We also observed increases in cholinergic and noradrenergic axon fluorescence periods of locomotion, which was accompanied by pupil dilation and nasal (forward) movement of both pupils. Locomotion was preceded by a rise in axonal fluorescence with a timing and amplitude that matched the subsequent pupil dilation, but axon fluorescence was more sustained than expected from the pupil dilation, suggesting that there is an additional physiological factor that affects cholinergic and noradrenergic axon activity in primary visual cortex during locomotion.


1994 ◽  
Vol 11 (5) ◽  
pp. 839-849 ◽  
Author(s):  
A. Michalski ◽  
B. M. Wimborne ◽  
G. H. Henry

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.


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