PECULIARITIES OF EMOTIONAL-BEHAVIORAL REACTIONS IN RATS WITH SIMULATING APNEA SLEEP SYNDROME

Abstract

Summary. Obstructive sleep apnea-hypopnea syndrome (OSAHS) – a pathological condition of pulmonary ventilation in patients over 10 seconds; during 7 hours of sleep apnea-hypopnea is registered at least 30 times. It is caused by periodic obstruction of the upper respiratory tract at the level of the throat; at the same time against the background of preservation of respiratory efforts the pulmonary ventilation is suspended and oxygen saturation of blood decreases; patients experience gross sleep fragmentation and excessive daytime sleepiness. Patients have a significant deterioration in quality of life due to insomnia disorders, and develop a symptom complex of organic disorders. For a deeper study of the pathogenetic mechanisms of OSAHS, it is advisable to use experimental models on small laboratory animals.

The aim of the study – to evaluate the features of emotional and behavioral reactions in rats when simulating their sleep apnea syndrome.

Materials and Methods. The study was performed on 42 white outbred male rats that were on a regular vivarium diet. To exclude accidental influences, all animals were in the same conditions and entered the experiment at the same time. Nonlinear white adult male rats weighing (200±10) g  were taken for the experiment in order to eliminate the fluctuations of the hormonal background. The animals were divided into 3 groups: I – rats which under barbiturate anesthesia were simulated obstructive sleep apnea (21 rats), II – rats, which underwent barbiturate anesthesia (14 rats), III – intact animals (7 rats). The animals were provided with medicated sleep by anesthesia. 1 % thiopental sodium solution was used for this purpose. Anesthetic at a dose of 60 mg/kg was injected intraperitoneally into the hypogastric area. Animals of the intact group received an intraperitoneally equivalent amount of isotonic NaCl solution. The physiological activity of rats was studied by the Buresh test in the open field. The features of emotional and behavioral reactions in animals, which simulated the syndrome of obstructive sleep apnea-hypopnea were investigated. To do this, a device was constructed which, with the help of an electromagnetic shutter, causes the two straps to be closed in time, between which a latex thin-walled coupling is fixed, worn on the muzzles of animals, the proximal part of which is close to the scalp. The animals were in a medicated sleep. The study was conducted on 4, 12 and 18 days.

Results. During the simulation of inspiratory apnea, their intrapleural pressure increased 5–6 times. We studied the emotional and behavioral responses of 42 rats on the test "open field" with an interval of 3 days, a total duration of 18 days. Deterioration of values of horizontal and vertical activity and indicators of vegetative balance on the background of anesthesia and, especially, in the simulation of obstructive sleep apnea syndrome, which showed their ability to impair adaptation, in contrast to intact animals.

Conclusions. For in-depth study of the phenomenon of obstructive sleep apnea-hypopnea, it is advisable to apply the proposed experimental model of inspiratory overlap of the oral and nasal lumens of animals for (2.2±0.2) second during each minute of sleep during anesthesia. When modeling obstructive sleep apnea-hypopnea in rats there are functional changes – a decrease in emotional and behavioral responses and autonomic balance, which indicates a pronounced violation of adaptive mechanisms.