Biology subjects

Amita, H.

Publications and source records attributed to Amita, H..

3 recordsLinked to original sources

bioRxiv2026

JEV helicase targets host MTOC and participates in the organization of pericentriolar viroplasm

Flaviviruses contribute significantly to the global disease burden and are known to remodel host organelles to their advantage. Centrosomal microtubule-organizing centres (MTOCs) having established role in cell division and signalling are also targeted by viruses. However, it remains uncertain whether they act as bystanders or actively engage in viral processes. Here, we elucidate the centrosome and cytoskeletal involvement during Japanese Encephalitis Virus (JEV) infection. Our virus-free expression studies revealed a centrosome-targeting region within the C-terminal helicase domain that mediates the association of JEV-NS3 with host MTOCs. When expressed exogenously, JEV-NS3 formed pericentriolar aggresomes resembling the helicase-containing viroplasm distribution pattern of infected cells. These pericentriolar viroplasm appears in the non-neuronal cell types with centriolar consequences while the neuronal cell types fail to show such phenotypes. Centriole depletion assays revealed the proviral role of centrosome, where the viroplasm organization depends on centrosomal MTOCs, and vimentin cages. Additionally, microtubule disruption and dynarrestin blockade assays emphasized the roles of microtubules and dynein in concentrating NS3-containing vesicular packets towards centrosomes, highlighting the centrosome-cytoskeleton axis as a potential target for intervention.

cell biology↗

bioRxiv2023

Neuronal mechanism of the encoding of socially familiar faces in the striatum tail

Although we can quickly locate a familiar person even in a crowd, the underlying neuronal mechanism remains unclear. Recently, we found that the striatum tail (STRt), which is part of the basal ganglia, is sensitive to long-term reward history. Here, we show that long-term value-coding neurons are involved in the detection of socially familiar faces. Many STRt neurons respond to facial images, especially to those of socially familiar persons. Additionally, we found that these face-responsive neurons also encode the stable values of many objects based on long-term reward experiences. Interestingly, the strength of neuronal modulation of social familiarity bias (familiar or unfamiliar) and object value bias (high-valued or low-valued) were positively correlated. These results suggest that both social familiarity and stable object-value information are mediated by a common neuronal mechanism. This mechanism may contribute to the rapid detection of familiar faces in real-world contexts. TeaserThe common mechanism mediating social familiarity and stable object-value information may contribute to rapid detection of familiar faces.

neuroscience↗

bioRxiv2019

Indirect pathway of caudate tail for choosing good objects in periphery

Choosing good objects is essential for real life, which is controlled mainly by the basal ganglia. For that, a subject need to not only find good objects, but reject bad objects. To reveal this rejection mechanism, we created a sequential saccade choice task for monkeys and studied the indirect pathway of caudate tail mediated by cvGPe (caudal-ventral globus pallidus externus). The inhibitory responses of cvGPe neurons to bad objects were smaller when the monkey made saccades to them by mistake. Moreover, experimental reduction of the inhibitory response by local injection of bicuculline (GABAA antagonist) disabled the monkey to reject bad objects. In conclusion, rejecting bad objects is crucial for goal-directed behavior, which is controlled by the indirect pathway in the basal ganglia.

neuroscience↗