CME Journal of Neurology and Neuroscience

At present, a number of epileptic attack forms are intractable (not sensitive to pharmacological treatment). Deep brain stimulation (DBS) is used as an alternative therapeutic procedure for pharmacoresistant psychiatric disorders. The results of using such methods have, however, contradictory. This is why structures whose stimulation is capable of inducing an antiseizure effect by preventing initiation and/or spread of epileptiform reactions have not yet been adequately identified. The aim of our study was to investigate the effects of short-term and long-term ventral tegmentum area (VTA) stimulation on local and generalized hippocampal seizure responses. Hippocampal seizure reactions were considered local if convulsive discharges were not registered in the electrical activity of the neocortex and behavioral seizures did not developed. It was shown that long-term (30 sec) stimulation of the VTA significantly reduced the development of local hippocampal seizure responses. It was also shown that with long-term (8-10 min) stimulation of the VTA, there is a strong and long-term inhibition of the convulsive reactions of the hippocampus. The present study shows that the ventral tegmental dopaminergic system, which is involved in the regulation of hippocampal theta rhythm and emotional responses, may trigger the activation of mechanisms that are characterized by anticonvulsant activity. The strong inhibitory effect of VTA stimulation on the hippocampal seizure responses is due to 1) regulation of the hippocampal theta rhythm, 2) potentiation of dopaminergic synapses, and 3) involvement of the reticular nucleus of the thalamus.