scholarly journals Activation of neuromodulatory axon projections in primary visual cortex during periods of locomotion and pupil dilation

2018 ◽  
Author(s):  
Rylan Scott Larsen ◽  
Emily Turschak ◽  
Tanya Daigle ◽  
Hongkui Zeng ◽  
Jun Zhuang ◽  
...  
Keyword(s):  
Visual Cortex ◽  
Primary Visual Cortex ◽  
Pupil Dilation ◽  
Cortical Function ◽  
Forward Movement ◽  
Physiological Factor ◽  
Two Photon Microscopy ◽  
Two Photon ◽  
Subcortical Nuclei

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.

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.

scholarly journals Astrocytes in the mouse visual cortex reliably respond to visual stimulation

2018 ◽  
Author(s):  
Keita Sonoda ◽  
Teppei Matsui ◽  
Haruhiko Bito ◽  
Kenichi Ohki
Keyword(s):  
Visual Cortex ◽  
Primary Visual Cortex ◽  
Common Mechanism ◽  
List Type ◽  
Visual Responses ◽  
Two Photon ◽  
Dual Color ◽  
Cross Correlation Analysis ◽  
Mouse Visual Cortex

AbstractAstrocytes are known to contact with a great number of synapses and may integrate sensory inputs. In the ferret primary visual cortex, astrocytes respond to a visual stimulus with a delay of several seconds with respect to the surrounding neurons. However, in the mouse visual cortex, it remains unclear whether astrocytes respond to visual stimulations. In this study, using dual-color simultaneous in vivo two-photon Ca2+ imaging of neurons and astrocytes in the awake mouse visual cortex, we examined the visual responsiveness of astrocytes and their precise response timing relative to the surrounding neurons. Neurons reliably responded to visual stimulations, whereas astrocytes often showed neuromodulator-mediated global activities, which largely masked small periodic activities. Administration of the selective α1-adrenergic receptor antagonist prazosin substantially reduced such global astrocytic activities without affecting the neuronal visual responses. In the presence of prazosin, astrocytes showed weak but consistent visual responses mostly at their somata. Cross-correlation analysis estimated that the astrocytic visual responses were delayed by approximately 5 s relative to the surrounding neuronal responses. In conclusion, our research demonstrated that astrocytes in the primary visual cortex of awake mice responded to visual stimuli with a delay of several seconds relative to the surrounding neurons, which may indicate the existence of a common mechanism of neuron–astrocyte communication across species.HighlightsWe performed dual-color in vivo two-photon Ca2+ imaging of neurons and astrocytes.α1-adrenoblocker prazosin substantially reduced global astrocytic activities.Astrocytes showed weak but reliable visual responses in the awake mouse visual cortex.Astrocytic visual responses were delayed by 5 s relative to the neuronal ones.

In vivo imaging of liver injury and regeneration by functional two-photon microscopy

2016 ◽  
Vol 54 (12) ◽  
pp. 1343-1404
Author(s):  
A Ghallab ◽  
R Reif ◽  
R Hassan ◽  
AS Seddek ◽  
JG Hengstler
Keyword(s):  
Liver Injury ◽  
In Vivo Imaging ◽  
Two Photon Microscopy ◽  
Two Photon

scholarly journals Retinotopic organization of primary visual cortex in glaucoma: Comparing fMRI measurements of cortical function with visual field loss

2007 ◽  
Vol 26 (1) ◽  
pp. 38-56 ◽  
Author(s):  
Robert O. Duncan ◽  
Pamela A. Sample ◽  
Robert N. Weinreb ◽  
Christopher Bowd ◽  
Linda M. Zangwill
Keyword(s):  
Visual Cortex ◽  
Visual Field ◽  
Primary Visual Cortex ◽  
Visual Field Loss ◽  
Cortical Function ◽  
Retinotopic Organization

Sensory Transmission is Bi-directionally Modulated by Astrocytic Ca2+ in Barrel Cortex of Behaving Mice

2021 ◽  
Author(s):  
Simeng Gu ◽  
Wei Wang ◽  
Kuan Zhang ◽  
Rou Feng ◽  
Naling Li ◽  
...  
Keyword(s):  
Sensory Input ◽  
Barrel Cortex ◽  
Synaptic Function ◽  
Metabolic Clearance ◽  
Sleep State ◽  
Two Photon Microscopy ◽  
Two Photon ◽  
Sensory Transmission

Abstract Different effects of astrocyte during sleep and awake have been extensively studied, especially for metabolic clearance by the glymphatic system, which works during sleep and stops working during waking states. However, how astrocytes contribute to modulation of sensory transmission during sleep and awake animals remain largely unknown. Recent advances in genetically encoded Ca2+ indicators have provided a wealth of information on astrocytic Ca2+, especially in their fine perisynaptic processes, where astrocytic Ca2+ most likely affects the synaptic function. Here we use two-photon microscopy to image astrocytic Ca2+ signaling in freely moving mice trained to run on a wheel in combination with in vivo whole-cell recordings to evaluate the role of astrocytic Ca2+ signaling in different behavior states. We found that there are two kinds of astrocytic Ca2+ signaling: a small long-lasting Ca2+ increase during sleep state and a sharp widespread but short-long-lasting Ca2+ spike when the animal was awake (fluorescence increases were 23.2 ± 14.4% for whisker stimulation at sleep state, compared with 73.3 ± 11.7% for at awake state, paired t-test, p < 0.01). The small Ca2+ transients decreased extracellular K+, hyperpolarized the neurons, and suppressed sensory transmission; while the large Ca2+ wave enhanced sensory input, contributing to reliable sensory transmission in aroused states. Locus coeruleus activation works as a switch between these two kinds of astrocytic Ca2+ elevation. Thus, we show that cortical astrocytes play an important role in processing of sensory input. These two types of events appear to have different pharmacological sources and may play a different role in facilitating the efficacy of sensory transmission.

Quantum Dots assisted and NIR-II Emissive In Vivo Two-photon microscopy

2021 ◽  
Author(s):  
Huwei Ni ◽  
Yalun Wang ◽  
Tao Tang ◽  
Wenbin Yu ◽  
Dongyu Li ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Two Photon Microscopy ◽  
Two Photon

Video-rate two-photon microscopy of cortical hemodynamics in-vivo

2006 ◽  
Author(s):  
Matthew Bouchard ◽  
Svetlana Ruvinskya ◽  
David A. Boas ◽  
Elizabeth M. C. Hillman
Keyword(s):  
Two Photon Microscopy ◽  
Two Photon

scholarly journals Impact of Body Site, Age, and Gender on the Collagen/Elastin Index by Noninvasive in vivo Vertical Two-Photon Microscopy

2017 ◽  
Vol 30 (5) ◽  
pp. 260-267 ◽  
Author(s):  
Carolin Czekalla ◽  
Karl-Heinz Schönborn ◽  
Nadine Döge ◽  
Sora Jung ◽  
Maxim E. Darvin ◽  
...  
Keyword(s):  
Body Site ◽  
Age And Gender ◽  
Two Photon Microscopy ◽  
Two Photon ◽  
And Gender
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