UDC

612.826+57.053:599.32

Authors

Al’bina А. Petrova*, Aleksey N. Inyushkin*
*Samara National Research University (Samara, Russian Federation)
Corresponding author: Aleksey Inyushkin; address: ul. Akademika Pavlova 1, Samara, 443011, Russian Federation;
е-mail: ainyushkin@mail.ru

Abstract

This paper assessed the role of neuropeptide Y as an entraining factor for neurons in the hypothalamic suprachiasmatic nucleus – the main circadian oscillator in humans and mammals. We studied the effect of 10 nM neuropeptide Y applications on spike activity and spike code parameters of neurons in rat suprachiasmatic nucleus in vitro. We used our own approach to the analysis of spike activity, which consists in calculating the distribution entropy of interspike intervals and mutual information between adjacent interspike intervals along with the determination of mean spike frequency. This allowed us to investigate the effect produced by neuropeptide Y not only on the level of cell activity, but also on the degree of irregularity in the generation of action potentials and on the patterning of spike activity. The analysis of the effect of neuropeptide Y revealed two types of response: a decrease (in 43.2 % of neurons) and an increase (in 9.9 % of neurons) in mean spike frequency. The rest of the neurons (46.9 %) had no changes in this activity parameter. In all recorded cells, treated as a single group (n = 81), a statistically significant decrease in the level of activity and an increase in mutual information between adjacent interspike intervals were revealed. The results obtained show that neuropeptide Y can influence the level of spike activity and spike code parameters of neurons in the hypothalamic suprachiasmatic nucleus.

Keywords

neuropeptide Y, circadian rhythms, brain neurons, spike activity, suprachiasmatic nucleus

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