Biology subjects

Chauhan, V.

Publications and source records attributed to Chauhan, V..

23 records · Page 2Linked to original sources

bioRxiv2020

The Grand Budapest Hotel: an fMRI dataset in response to a socially-rich, naturalistic movie

Naturalistic stimuli evoke strong, consistent, and information-rich patterns of brain activity, and engage large extents of the human brain. They allow researchers to compare highly similar brain responses across subjects, and to study how complex representations are encoded in brain activity. Here, we describe and share a dataset where 25 subjects watched part of the feature film "The Grand Budapest Hotel" by Wes Anderson. The movie has a large cast with many famous actors. Throughout the story, the camera shots highlight faces and expressions, which are fundamental to understand the complex narrative of the movie. This movie was chosen to sample brain activity specifically related to social interactions and face processing. This dataset provides researchers with fMRI data that can be used to explore social cognitive processes and face processing, adding to the existing neuroimaging datasets that sample brain activity with naturalistic movies.

neuroscience↗

bioRxiv2020

Identification of a long non-coding RNA regulator of liver carcinoma cell survival

ABSTRACTGenomic studies have significantly improved our understanding of hepatocellular carcinoma (HCC) biology and have led to the discovery of multiple protein-coding genes driving hepatocarcinogenesis. In addition, these studies have identified thousands of new non-coding transcripts deregulated in HCC. We hypothesize that some of these transcripts may be involved in disease progression. Long non-coding RNAs are a large class of non-coding transcripts which participate in the regulation of virtually all cellular functions. However, a majority of lncRNAs remain dramatically understudied. Here, we applied a pooled shRNA-based screen to identify lncRNAs essential for HCC cell survival. We validated our screening results using RNAi, CRISPRi, and antisense oligonucleotides. We found a lncRNA, termed ASTILCS, that is critical for HCC cell growth and is overexpressed in tumors from HCC patients. We demonstrated that HCC cell death upon ASTILCS knockdown is associated with apoptosis induction and downregulation of a neighboring gene, Protein Tyrosine Kinase 2 (PTK2), a crucial protein for HCC cell survival. Taken together, our study describes a new, non-coding RNA regulator of HCC.Competing Interest StatementThe authors have declared no competing interest.View Full Text

cancer biology↗

bioRxiv2020

Keratins and Plakin family cytolinker proteins control the length of epithelial microridge protrusions

Actin filaments and microtubules create diverse cellular protrusions, but intermediate filaments, the strongest and most stable class of cytoskeletal elements, are not known to directly participate in the formation of protrusions. Here we show that Keratin intermediate filaments directly regulate the morphogenesis of microridges, elongated protrusions from mucosal epithelial cells arranged in elaborate fingerprint-like patterns. Developing microridges on zebrafish skin cells contained both Actin and Keratin filaments. Keratin filaments maintained microridges upon F-actin disruption, and overexpressing Keratins lengthened microridges. Envoplakin and Periplakin, Plakin family cytolinkers that bind to F-actin and Keratins, localized to microridges and were required for their morphogenesis. Strikingly, Plakin protein levels directly determined microridge length. An actin-binding domain of Periplakin was required to initiate microridge morphogenesis, whereas Periplakin-Keratin binding was required to stabilize and elongate microridges. Our results thus separate microridge morphogenesis into two steps with differential requirements for cytoskeletal elements, expand our understanding of intermediate filament functions, and identify microridges as cellular protrusions that integrate actin and intermediate filaments.

cell biology↗

bioRxiv2018

Familiarity facilitates detection of angry expressions

Personal familiarity facilitates rapid and optimized detection of faces. In this study, we investigated whether familiarity associated with faces can also facilitate the detection of facial expressions. Models of face processing propose that face identity and face expression detection are mediated by distinct pathways. We used a visual search paradigm to assess if facial expressions of emotion (anger and happiness) were detected more rapidly when produced by familiar as compared to unfamiliar faces. We found that participants detected an angry expression 11% more accurately and 135 ms faster when produced by familiar as compared to unfamiliar faces while happy expressions were detected with equivalent accuracies and at equivalent speeds for familiar and unfamiliar faces. These results suggest that detectors in the visual system dedicated to processing features of angry expressions are optimized for familiar faces.

neuroscience↗

bioRxiv2018

How familiarity warps representation in the face space

Recognition of familiar as compared to unfamiliar faces is robust and resistant to marked image distortion or degradation. Here we tested the flexibility of familiar face recognition with a morphing paradigm where the appearance of a personally familiar face was mixed with the appearance of a stranger. The aim was to assess how categorical boundaries for recognition of identity are affected by familiarity. We found a narrower categorical boundary for the identity of personally familiar faces when they were mixed with unfamiliar identities as compared to the control condition, in which the appearance of two unfamiliar faces were mixed. Our results suggest that familiarity warps the representational geometry of face space, amplifying perceptual distances for small changes in the appearance of familiar faces that are inconsistent with the structural features that define their identities.

neuroscience↗