Introduction. Worldwide studies related to the caffeine use are quite relevant. The substance has a multifaceted influence on the organs and the body on the whole, which needs further investigation. Since the study of mechanisms of influence of substances differs by their nature, their duration and intensity on the CNS structures, a chronic experiment was carried out by means of the electro-encephalography method, the removal of bioelectric activity from the ergotropic zone of the hypothalamus is in most cases the only indicator of the determination of the central nervous processes under the caffeine influence within the study of the functional state of the corresponding part of the brain.
Purpose. The aim of the study is to determine the caffeine influence on the modulation of indices of the bioelectric activity of the ergotropic zone of hypothalamus of rats of different age groups.
Materials and methods. Experiments were carried out on non-linear white outbred male rats. The animals were distributed into studied groups using the classification of age groups of laboratory animals by IP. Zapadniuk. According to this classification male rats were divided into IV groups: I group (2.5 months) – the juvenile puberty period, II group (eight months) – the young age of the reproductive period, III group (fourteen months) – the mature age of the reproductive period, IV group (21 months) – rats of presenile age of the pronounced senile changes period (IV group). Male rats of control groups had a normal diet, whereas male rats in the experimental group had daily intake of caffeine 150 mg/kg (LD50 = 192mg/kg) per month. Rats of the studied groups underwent Electric Hypothalamus Test (EGtG) of the ergotropic zone.
Results. In juvenile male rats of the control group, the prevalence of slow-wave synchronization processes was observed, which was manifested in the form of elevated low-frequency high-amplitude bioelectric activity in the ergotropic zone of rats’ hypothalamus. After the monthly caffeine consumption by males of the youngest age group, the domination of functional activation of the synchronizing effect on the bioelectric activity of the hypothalamus studied area continued, despite the fact that all EGtG components had significantly lower values as compared with control values. The young age of males in both the control and experimental groups was characterized by the dominance of high-frequency EGtG components in the variation of spectral absolute and normalized capacities. Mature males of the control group were characterized by the predominance of low frequency oscillations and a significant predominance of delta-like activity in the EGtG. Instead, in male rats of the experimental group with a change of age to the mature one, the increase in the power values of all EGtG components was observed, while a significant increase in high-frequency EGtG components in the corresponding area of the hypothalamus should be noted. Proceeding from this, we can talk about the advantage of desynchronizing effects on the bioelectric activity of the ergotropic zone of the hypothalamus of male rats over the synchronizing one under the caffeine influence. In males of presenile age, the prevalence of low-frequency EGtG oscillations was noted after the monthly caffeine consumption.
Conclusions. It has been established that with age, male rats in control groups have shown the decrease in the indices of high-frequency components of Electric Hypothalamus Test (EGtG), removed from the hypothalamus ergotropic zone, which is the evidence of the powerful synchronizing mechanisms functioning. It has been proved that the caffeine influence on the bioelectric activity of the corresponding area of hypothalamus with age causes the increase of indicators of high-frequency capacities, which testifies to the predominance of desynchronizing processes.
Article recieved: 11.06.2018
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