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Oshiro, M.

Publications and source records attributed to Oshiro, M..

2 recordsLinked to original sources

Artificial hibernation uncovers distinct interaction dynamics in functional and pathological state change

Neural population activity can reorganize without disrupting function, but how such changes differ from those associated with pathology remains unknown. Artificial hibernation, Q-neuron-induced hypothermia and hypometabolism (QIH), causes extensive synaptic remodeling in the hippocampus without erasing established memories, allowing us to examine how extensive network reorganization can occur without lasting functional impairment. Longitudinal calcium imaging showed that hippocampal activity recovered after QIH without returning to its pre-hibernation population configuration. Instead, QIH reorganized neuronal activity patterns and coactivity beyond representational drift. Electrophysiological recordings revealed that this reorganization of neuronal interactions depended on the preceding network state. In mice subjected to kainic acid-induced status epilepticus, QIH reduced seizure-associated increases in neuronal interactions and spike coactivity during sharp-wave ripples. Over the following 50 days, the divergence of hippocampal LFP trajectories was constrained, and the progressive development of electrophysiological and histological pathology was attenuated. These findings suggest that controlled, extensive reorganization of neural population activity can prevent the progression toward pathological network states, with changes in neuronal interactions, particularly sharp-wave ripple-associated coactivity, accompanying this process.

neuroscience↗

Kinetic modeling of continuous meta-fermentation quantifies metabolic activity in a complex microbial system

One of the serious drawbacks of a complex microbial system is the difficulty in quantifying the metabolic activity of each microorganism. A kinetic model of predominant microbial species was constructed for continuous meta-fermentation in a complex microbial system at several dilution rates (D). The introduction of biomass and lactic acid inhibition terms improved model accuracies at D = 0.05 h-1 and 0.4 h-1, respectively. The coefficient of determination (R2) and root mean square error (RMSE) improved from 0.577 and 5.21 to 0.972 and 0.759, respectively, with the inhibition term at D = 0.05 h-1. The inhibition terms resulted in good R{superscript 2} (0.996) and RMSE (1.27) values at D = 0.4 h-1. By solving the Michaelis-Menten equation in the constructed models, the species flux (SF) was calculated to estimate the metabolic activity (formation and consumption) of each microorganism. At D = 0.05 h-1, Caldibacillus hisashii contributed to lactic acid production at 0.333 g/L/h, whereas Clostridium cochlearium consumed lactic acid at 0.203 g/L/h, suggesting cross-feeding of a metabolite. It is therefore possible to account for consumption that cannot be considered in gene-derived calculations, indicating that this is a promising analytical method for investigating the dynamic behavior of complex microbial systems. Kinetic models for continuous meta-fermentation at several D values were developed. A new metabolic analysis method is proposed to estimate the activity of microbial species in a complex microbial system.

bioinformatics↗