ENDOGENOUS AND EXOGENOUS NEUROSTEROIDAL MODULATION OF MEMORY IN RATS WITH ALCOHOL DEPENDENCE AND AGGRESSIVE BEHAVIOR

Abstract

Alcoholism and chronic stress lead to impaired cognitive functions, which are regulated, in particular, by neurosteroid hormones. Exogenous administration of progesterone is one of the ways to influence the brain system of hormonal and neurotransmitter regulation. The effect of intranasal administration of low doses of progesterone on endogenous neurosteroid modulation of working and spatial memory in male rats with alcohol dependence and aggressive behavior was investigated. Alcohol dependence in male rats was modeled by voluntary intake of bread soaked in ethanol solution at a dose of 1.2 g/kg for 30 days. Aggressiveness was determined using the sensory contact method and the “partition” test. To study memory processes in rats, neuroethological methods of testing working (recognition of new objects) and spatial (orientation in the Barnes maze) memory were used. Progesterone was administered intranasally at a dose of 80 μg per rat for 10 days. Progesterone, testosterone, and cortisol levels were measured in the frontal neocortex (FC), hippocampus, and serum using enzyme-linked immunosorbent assay kits. The stimulatory effect of alcoholization on spatial memory and impairment of working memory in male rats with aggressive behavior was found. Zoosocial conflict on the background of prolonged alcohol consumption leads to impaired object recognition and spatial orientation against the background of neurosteroid imbalance: a decrease in progesterone and testosterone content in the FC, hippocampus, serum, and an increase in cortisol levels in these structures. Intranasal administration of progesterone to rats with alcohol dependence and aggressive behavior offsets the negative effects of confrontational relationships on working memory processes, restores the acquired experience to the baseline (however, the processes of object differentiation remain weakened); leads to improved spatial memory. The favorable effects of progesterone on memory are accompanied by a decrease in the imbalance of hormonal influences in brain structures with the restoration of progesterone and testosterone concentrations in the FC, hippocampus and serum against the background of weakening of stress-induced glucocorticoid activity. Therefore, intranasal administration of low doses of progesterone improves working and spatial memory in male rats with alcohol dependence and aggressive behavior due to the tendency to restore the balance of hormones (progesterone, testosterone, cortisol) in the brain structures responsible for memory.