Age-related changes in the spiking activity of neurons in the hypothalamic ventromedial nucleus

Authors

DOI:

https://doi.org/10.33910/2687-1270-2025-6-2-198-211

Keywords:

hypothalamus, ventromedial nucleus, neurophysiology, spike activity, aging

Abstract

The mediobasal hypothalamus, including the ventromedial nucleus (VMN), is integral to the regulation of aging. This study demonstrates a significant decline in the median spike rate within the VMN across age groups, decreasing from 1.32 spikes/s in young rats to 0.71 spikes/s in adults and 0.84 spikes/s in aged animals. The distribution of firing rates was unimodal in all cohorts, with the predominant rate being 0.5–1.5 spikes/s in young animals, up to 1 spike/s in adults, and up to 0.5 spikes/s in aged rats. Neuronal classification based on interspike interval histograms, normalized risk functions, and statistical analysis revealed six distinct discharge patterns: 1) random discharge, 2) wide interspike interval distribution, 3) rhythmic discharge, 4) long-tail interval histogram, 5) short burst discharges, and 6) short bursts with a wide interval distribution. While young rats exhibited a predominance of neurons with random discharge, the proportion of this group decreased by half in aged animals, accompanied by a concurrent increase in neurons displaying a long-tail interval histogram. Furthermore, aged rats showed significantly elevated coefficients of variation, skewness, and kurtosis, indicating the emergence of complex, higher-order patterns in neuronal firing with advancing age.

References

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Published

2025-12-28

Issue

Vol. 6 No. 2 (2025)

Section

Experimental articles

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Copyright (c) 2025 Andrey A. Spirichev, Petr M. Masliukov, Eugenyi V. Salnikov, Konstantin Yu. Moiseev

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