Biology subjects

Soma, S.

Publications and source records attributed to Soma, S..

6 recordsLinked to original sources

bioRxiv2025

AgRP Neuronal Suppression by Spontaneous Movement Encodes Exercise Reinforcement

Hypothalamic agouti-related peptide (AgRP) neurons that drive hunger-related behaviors are activated during energy deficit, encode negative valence but can be inhibited even by perception of food without digestion. Here, we show that in head-fixed mice, discrete motor actions such as spontaneous walking and conditioned licking rapidly suppress AgRP neuron activity. This suppression persisted throughout movement and terminated upon cessation, which was independent of food perception or conditioned cues. The degree of suppression was positively correlated with movement vigor. While optogenetic enhancement of AgRP neuron suppression did not initiate movement, it promoted reinforcement of concurrent walking behavior. These findings unmask that spontaneous, low intensity physical activity can reduce AgRP neuron activity reinforcing concurrent movement/exercise with implications for systemic health benefits.

neuroscience↗

bioRxiv2025

Data-Driven Feed Optimization for Sustainable Aquaculture through Integrated Omics Analysis and Two-stage Bayesian optimization

In aquaculture and livestock farming, developing feed that promotes efficient growth while minimizing environmental impact is crucial for sustainability. We developed a data-driven feed optimization system (DFOS) that integrates omics analysis with machine learning-based optimization technologies. First, DFOS employed Bayesian optimization (BO) to identify the optimal proportions of proteins and lipids, which are crucial feed components. Simultaneously, omics analysis was conducted to assess the physiological response of the targets to a given feed and identify key dietary components essential for growth. Next, BO was used to efficiently modify the combination and proportion of the specific additives identified in the first stage. We demonstrated the efficacy of DFOS by applying it to develop a new feed for the high-demand leopard coral grouper (Plectropomus leopardus) in Southeast Asia. This system provides an efficient data-driven framework for feed optimization across aquaculture and livestock, contributing significantly to more sustainable and productive farming practices.

ecology↗

bioRxiv2024

Early disruption of entorhinal dopamine in a knock-in model of Alzheimer's disease

The entorhinal cortex (EC) is a critical brain area for memory formation, while also the region exhibiting the earliest histological and functional alterations in Alzheimers disease (AD). The EC thus has been long hypothesized as one of the originating brain areas of AD pathophysiology, although circuit mechanisms causing its selective vulnerability remain poorly understood. We found that dopamine neurons projecting their axons to the lateral EC (LEC), critical for memory formation in healthy brains, become dysfunctional and cause memory impairments in early AD brains. In amyloid precursor protein knock-in mice with associative memory impairment, LEC dopamine activity and associative memory encoding of LEC layer 2/3 neurons were disrupted in parallel from the early pathological stage. Optogenetic reactivation of LEC dopamine fibers, as well as L- DOPA treatment, rescued associative learning behavior. These results suggest that dysfunction of LEC-projecting dopamine neurons underlies memory impairment in AD from early stages, pointing to a need for clinical investigation of LEC dopamine in AD patients.

neuroscience↗

bioRxiv2022

Human Lung-resident Mucosal-Associated Invariant T cells are Abundant, Express Antimicrobial Proteins, and are Cytokine Responsive

Mucosal-associated Invariant T (MAIT) cells are an innate-like T cell subset that recognize a broad array of microbial pathogens, including respiratory pathogens. Here we investigate the transcriptional profile of MAIT cells localized to the human lung, and postulate that MAIT cells may play a role in maintaining homeostasis at this mucosal barrier. Using the MR1/5-OP-RU tetramer, we identified MAIT cells and non-MAIT CD8+ T cells in lung tissue not suitable for transplant from human donors. We used RNA-sequencing of MAIT cells compared to non-MAIT CD8+ T cells to define the transcriptome of MAIT cells in the human lung. We show that, as a population, lung MAIT cells are polycytotoxic, secrete the directly antimicrobial molecule IL-26, express genes associated with persistence, and selectively express cytokine and chemokine-related molecules distinct from other lung-resident CD8+ T cells, such as interferon-{gamma}- and IL-12-receptors. These data highlight MAIT cells predisposition to rapid pro-inflammatory cytokine responsiveness and antimicrobial mechanisms in human lung tissue, concordant with findings of blood-derived counterparts, and support a function for MAIT cells as early sensors in the defense of respiratory barrier function.

immunology↗

bioRxiv2022

Hippocampal CA1 represents action and reward events instantly compared to the superficial and deep layers of the lateral entorhinal cortex

The entorhinal cortex (EC) is the main interface between the hippocampus and the neocortex. The EC plays a critical role in learning and memory. We investigated the neuronal representation of behavioral events during operant learning in the hippocampal-entorhinal circuit of head-fixed rats. Both CA1 and lateral entorhinal cortex (LEC) neurons develop task-related activities after learning. Among diverse task-related activities, we compared the transient peak activities that represent action and reward and found a distinct difference in the timing of behavioral event representation between CA1 and LEC. CA1 represents action and reward events in close to real-time, whereas both the superficial and deep layers of the LEC showed delayed representation of those events. Our results suggest that subpopulations exist within which CA1 and LEC neurons process the information in a different order from the anatomically defined hippocampal-entorhinal circuit.

neuroscience↗

bioRxiv2019

Disrupted remapping of place cells and grid cells in knock-in model of Alzheimer’s disease

Patients with Alzheimers disease (AD) frequently suffer from spatial memory impairment and wandering behavior, but brain circuits causing such symptoms remain largely unclear. In healthy brains, spatially-tuned hippocampal place cells and entorhinal grid cells represent distinct spike patterns in different environments, a circuit function called "remapping" that underlies pattern separation of spatial memory. We investigated whether knock-in expression of mutated amyloid precursor protein deteriorates the remapping of place cells and grid cells. We found that the remapping of CA1 place cells was disrupted although their spatial tuning was only mildly diminished. Grid cells in the medial entorhinal cortex (MEC) were impaired, sending severely disrupted remapping signals to the hippocampus. Furthermore, fast gamma oscillations were disrupted in both CA1 and MEC, resulting in impaired fast gamma coupling in the MEC[->]CA1 circuit. These results point to the link between grid cell impairment and remapping disruption as a circuit mechanism causing spatial memory impairment in AD.

pathology↗