AUDIOGENIC SEIZURE SUPPRESSION BY VENTRAL TEGMENTAL AREA STIMULATION

The audiogenic seizure (AGS) model is one of several experimental models used to study epilepsy and identify underlying mechanisms. Dopamine plays an important role in epileptogenesis and dopaminergic neurons of ventral tegmental area (VTA) have extensive connections with many brain structures. Despite of this there are no data on the influence of this structure on the audiogenic seizure responses of the brain. The main aim of our study was to investigate the influence of the VTA on the development of audiogenic seizure reactions in genetically epilepsy-prone rats. The novelty of these article lies not only in the observation of changes in the development/course of audiogenic seizure reactions caused by stimulation of the VTA, but also in taking into account the localization of the epileptogenic focus, which, in our opinion, is especially important for the scientific analysis of this type of research. The inferior and superior colliculus has prominent descending projections to several areas of the reticular formation, which may sub serve the direct AGS efferent pathway. The experiments conducted showed that in response to stimulation of the VTA, the latency and duration of the first wild run do not undergo significant changes. The experiments showed a significant increase in the duration of the pause between the first and second wild runs and a significant decrease in the duration of the second wild run. Furthermore, we observed a significant decrease in behavioral seizure activity after the second wild run, leading to its complete disappearance. Structures receiving synaptic inputs from the ventral tegmental area deserve special attention. One such structure is the reticular nucleus of the thalamus (TRN). It has been shown that stimulation of TRN causes inhibition of neurons in those brainstem structures that are involved in motor reactions of the spinal cord. Therefore, it can be hypothesized that the TRN modulate the brainstem regions responsible for motor responses during audiogenic seizures. From our results we can conclude: The VTA plays an important role in epileptogenesis, which is apparently associated with the inhibitory effect of dopamine on the motor manifestations of seizures. Therefore, VTA as a brain dopaminergic nucleus, may be a suitable target for DBS anticonvulsant action.