scholarly journals Curvature-processing domains in primate V4

eLife ◽  
2020 ◽  
Vol 9 ◽  
Author(s):  
Rendong Tang ◽  
Qianling Song ◽  
Ying Li ◽  
Rui Zhang ◽  
Xingya Cai ◽  
...  
Keyword(s):  
Calcium Imaging ◽  
Visual Object ◽  
Visual Object Recognition ◽  
Intrinsic Signal ◽  
Two Photon ◽  
Contour Shape ◽  
Wide Range ◽  
Shape Tuning ◽  
Common Shape

Neurons in primate V4 exhibit various types of selectivity for contour shapes, including curves, angles, and simple shapes. How are these neurons organized in V4 remains unclear. Using intrinsic signal optical imaging and two-photon calcium imaging, we observed submillimeter functional domains in V4 that contained neurons preferring curved contours over rectilinear ones. These curvature domains had similar sizes and response amplitudes as orientation domains but tended to separate from these regions. Within the curvature domains, neurons that preferred circles or curve orientations clustered further into finer scale subdomains. Nevertheless, individual neurons also had a wide range of contour selectivity, and neighboring neurons exhibited a substantial diversity in shape tuning besides their common shape preferences. In strong contrast to V4, V1 and V2 did not have such contour-shape-related domains. These findings highlight the importance and complexity of curvature processing in visual object recognition and the key functional role of V4 in this process.

scholarly journals Seizures start as silent microseizures by neuronal ensembles

2018 ◽  
Author(s):  
Michael Wenzel ◽  
Jordan P. Hamm ◽  
Darcy S. Peterka ◽  
Rafael MD Yuste
Keyword(s):  
Calcium Imaging ◽  
Travelling Wave ◽  
Inhibitory Neurons ◽  
Neural Activation ◽  
Calcium Dynamics ◽  
Neuronal Ensembles ◽  
Two Photon ◽  
Step Model

AbstractUnderstanding seizure formation and spread remains a critical goal of epilepsy research. While many studies have documented seizure spread, it remains mysterious how they start. We used fast in-vivo two-photon calcium imaging to reconstruct, at cellular resolution, the dynamics of focal cortical seizures as they emerge in epileptic foci (intrafocal), and subsequently propagate (extrafocal). We find that seizures start as intrafocal coactivation of small numbers of neurons (ensembles), which are electrographically silent. These silent “microseizures” expand saltatorily until they break into neighboring cortex, where they progress smoothly and first become detectable by LFP. Surprisingly, we find spatially heterogeneous calcium dynamics of local PV interneuron sub-populations, which rules out a simple role of inhibitory neurons during seizures. We propose a two-step model for the circuit mechanisms of focal seizures, where neuronal ensembles first generate a silent microseizure, followed by widespread neural activation in a travelling wave, which is then detected electrophysiologically.

scholarly journals A dual role of prestimulus spontaneous neural activity in visual object recognition

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Ella Podvalny ◽  
Matthew W. Flounders ◽  
Leana E. King ◽  
Tom Holroyd ◽  
Biyu J. He
Keyword(s):  
Object Recognition ◽  
Neural Activity ◽  
Dual Role ◽  
Visual Object ◽  
Visual Object Recognition ◽  
Spontaneous Neural Activity

scholarly journals Community-based benchmarking improves spike rate inference from two-photon calcium imaging data

2017 ◽  
Author(s):  
Philipp Berens ◽  
Jeremy Freeman ◽  
Thomas Deneux ◽  
Nicolay Chenkov ◽  
Thomas McColgan ◽  
...  
Keyword(s):  
Neural Activity ◽  
Calcium Imaging ◽  
Indirect Measurement ◽  
Generative Models ◽  
Imaging Data ◽  
Crowd Sourcing ◽  
Two Photon ◽  
Wide Range ◽  
Improved Performance ◽  
Highly Correlated

In recent years, two-photon calcium imaging has become a standard tool to probe the function of neural circuits and to study computations in neuronal populations. However, the acquired signal is only an indirect measurement of neural activity due to the comparatively slow dynamics of fluorescent calcium indicators. Different algorithms for estimating spike trains from noisy calcium measurements have been proposed in the past, but it is an open question how far performance can be improved. Here, we report the results of the spikefinder challenge, launched to catalyze the development of new spike inference algorithms through crowd-sourcing. We present ten of the submitted algorithms which show improved performance compared to previously evaluated methods. Interestingly, the top-performing algorithms are based on a wide range of principles from deep neural networks to generative models, yet provide highly correlated estimates of the neural activity. The competition shows that benchmark challenges can drive algorithmic developments in neuroscience.

scholarly journals Deficits in higher visual area representations in a mouse model of Angelman syndrome

2020 ◽  
Vol 12 (1) ◽  
Author(s):  
Leah B. Townsend ◽  
Kelly A. Jones ◽  
Christopher R. Dorsett ◽  
Benjamin D. Philpot ◽  
Spencer L. Smith
Keyword(s):  
Visual Cortex ◽  
Mouse Model ◽  
Primary Visual Cortex ◽  
Angelman Syndrome ◽  
Calcium Imaging ◽  
Neurodevelopmental Disorders ◽  
Synaptic Function ◽  
Strong Response ◽  
Intrinsic Signal ◽  
Two Photon

Abstract Background Sensory processing deficits are common in individuals with neurodevelopmental disorders. One hypothesis is that deficits may be more detectable in downstream, “higher” sensory areas. A mouse model of Angelman syndrome (AS), which lacks expression of the maternally inherited Ube3a allele, has deficits in synaptic function and experience-dependent plasticity in the primary visual cortex. Thus, we hypothesized that AS model mice have deficits in visually driven neuronal responsiveness in downstream higher visual areas (HVAs). Methods Here, we used intrinsic signal optical imaging and two-photon calcium imaging to map visually evoked neuronal activity in the primary visual cortex and HVAs in response to an array of stimuli. Results We found a highly specific deficit in HVAs. Drifting gratings that changed speed caused a strong response in HVAs in wildtype mice, but this was not observed in littermate AS model mice. Further investigation with two-photon calcium imaging revealed the effect to be largely driven by aberrant responses of inhibitory interneurons, suggesting a cellular basis for higher level, stimulus-selective cortical dysfunction in AS. Conclusion Assaying downstream, or “higher” circuitry may provide a more sensitive measure for circuit dysfunction in mouse models of neurodevelopmental disorders. Trial registration Not applicable.

scholarly journals PatchWarp: Corrections of non-uniform image distortions in two-photon calcium imaging data by patchwork affine transformations

2021 ◽  
Author(s):  
Ryoma Hattori ◽  
Takaki Komiyama
Keyword(s):  
Neural Activity ◽  
Calcium Imaging ◽  
Motion Correction ◽  
Extended Period ◽  
Affine Transformations ◽  
Imaging Data ◽  
Full Field ◽  
Two Photon ◽  
Automated Method ◽  
Wide Range

Two-photon microscopy has been widely used to record the activity of populations of individual neurons at high spatial resolution in behaving animals. The ability to perform imaging for an extended period of time allows the investigation of activity changes associated with behavioral states and learning. However, imaging often accompanies shifts of the imaging field, including rapid (~100ms) translation and slow, spatially non-uniform distortion. To combat this issue and obtain a stable time series of the target structures, motion correction algorithms are commonly applied. However, typical motion correction algorithms are limited to full field translation of images and are unable to correct non-uniform distortions. Here, we developed a novel algorithm, PatchWarp, to robustly correct slow image distortion for calcium imaging data. PatchWarp is a two-step algorithm with rigid and non-rigid image registrations. To correct non-uniform image distortions, it splits the imaging field and estimates the best affine transformation matrix for each of the subfields. The distortion-corrected subfields are stitched together like a patchwork to reconstruct the distortion-corrected imaging field. We show that PatchWarp robustly corrects image distortions of calcium imaging data collected from various cortical areas through glass window or GRIN lens with a higher accuracy than existing non-rigid algorithms. Furthermore, it provides a fully automated method of registering images from different imaging sessions for longitudinal neural activity analyses. PatchWarp improves the quality of neural activity analyses and would be useful as a general approach to correct image distortions in a wide range of disciplines.

The role of action representations in visual object recognition

2006 ◽  
Vol 174 (2) ◽  
pp. 221-228 ◽  
Author(s):  
Hannah Barbara Helbig ◽  
Markus Graf ◽  
Markus Kiefer
Keyword(s):  
Object Recognition ◽  
Visual Object ◽  
Visual Object Recognition ◽  
Action Representations

scholarly journals Molecular Mechanisms for Frequency Specificity in a Drosophila Hearing Organ

2021 ◽  
Author(s):  
Yufei Hu ◽  
Yinjun Jia ◽  
Tuantuan Deng ◽  
Ting Liu ◽  
Wei Zhang
Keyword(s):  
Calcium Imaging ◽  
High Frequency ◽  
Molecular Mechanisms ◽  
Sound Frequency ◽  
Chordotonal Organ ◽  
Frequency Specificity ◽  
Wide Range ◽  
Hearing Organ

Discrimination for sound frequency is essential for auditory communications in animals. Here, by combining in vivo calcium imaging and behavioral assay, we found that Drosophila larvae can sense a wide range of sound frequency and the behavioral specificity is mediated with the selectivity of the lch5 chordotonal organ neurons to sounds that forms a combinatorial coding of frequency. We also disclosed that Brivido1 (Brv1) and Piezo-like (Pzl), each expresses in a subset of lch5 neurons and mediate hearing sensation to certain frequency ranges. Intriguingly, mouse Piezo2 can rescue pzl-mutant's phenotypes, suggesting a conserved role of the Piezo family proteins in high-frequency hearing.

scholarly journals Opposing Roles of apolipoprotein E in aging and neurodegeneration

2019 ◽  
Vol 2 (1) ◽  
pp. e201900325 ◽  
Author(s):  
Eloise Hudry ◽  
Jacob Klickstein ◽  
Claudia Cannavo ◽  
Rosemary Jackson ◽  
Alona Muzikansky ◽  
...  
Keyword(s):  
Apolipoprotein E ◽  
Calcium Imaging ◽  
Brain Function ◽  
Neural Circuits ◽  
Evoked Responses ◽  
Neuronal Responses ◽  
Neuronal Function ◽  
Two Photon ◽  
Synapse Loss

Apolipoprotein E (APOE) effects on brain function remain controversial. Removal of APOE not only impairs cognitive functions but also reduces neuritic amyloid plaques in mouse models of Alzheimer’s disease (AD). Can APOE simultaneously protect and impair neural circuits? Here, we dissociated the role of APOE in AD versus aging to determine its effects on neuronal function and synaptic integrity. Using two-photon calcium imaging in awake mice to record visually evoked responses, we found that genetic removal of APOE improved neuronal responses in adult APP/PSEN1 mice (8–10 mo). These animals also exhibited fewer neuritic plaques with less surrounding synapse loss, fewer neuritic dystrophies, and reactive glia. Surprisingly, the lack of APOE in aged mice (18–20 mo), even in the absence of amyloid, disrupted visually evoked responses. These results suggest a dissociation in APOE’s role in AD versus aging: APOE may be neurotoxic during early stages of amyloid deposition, although being neuroprotective in latter stages of aging.

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