CHANGES IN THE LEVELS OF INHIBITORY AND EXCITATORY AMINO ACIDS AND NEUROPHYSIOLOGY CHARACTERISTICS IN THE BRAIN STRUCTURES OF FEMALE RATS WITH COBALT EPILEPTOGENIC FOCUS DURING DIFFERENT PHASES OF THE ESTROUS CYCLE

Abstract

Rats with cobalt epilepsy in the estrous cycle revealed fluctuation of the levels of inhibitory neurotransmitters (especially GABA), but not of excitatory. The most significant changes were found out in the contralateral cortex, where the levels of GABA and glycine considerably decreased during the diestrus-2 phase (corresponding to menstruation). Neurophysiology characteristics indicate the increasing of epileptic activity mainly in the contralateral cortex during the diestrus-2 phase. These data indicate a close interaction between the ovarian hormonal system and the GABA-ergic system in the mechanisms of seizures states. Cyclical fluctuations of steroid hormones are of essential meaning for the course of epilepsy during the menstrual cycle.

Keywords

• amino acids
• cobalt epilepsy model
• estrous cycle
• epileptiform activity