Potential Protective Effects of Chronic Anterior Thalamic Nucleus Stimulation on Hippocampal Neurons in Epileptic Monkeys.

ABSTRACT

BACKGROUND: Stimulation of the anterior nucleus of the thalamus (ANT) is effective in seizure reduction, but the mechanisms underlying the beneficial effects of ANT stimulation are unclear. OBJECTIVE: To assess the beneficial effects of ANT stimulation on hippocampal neurons of epileptic monkeys. METHODS: Chronic ANT stimulation was applied to kainic acid-induced epileptic monkeys. Behavioral seizures were continuously monitored. Immunohistochemical staining and western blot assays were performed to assess the hippocampal injury and the effects of ANT stimulation. RESULTS: The frequency of seizures was 42.8% lower in the stimulation group compared with the sham-stimulation group. Immunohistochemical staining and western blot analyses indicated that neuronal loss and apoptosis were less severe and that neurofilament synthesis was enhanced in the stimulation monkeys compared with the sham-stimulation group. These data showed that the hippocampal injury was less severe in monkeys in the stimulation group than in those in the sham-stimulation group. CONCLUSIONS: Our data suggest that chronic ANT stimulation may exert protective effects on hippocampal neurons and boost the regeneration of neuronal fibers. These effects may be closely related to the mechanisms of ANT stimulation in epilepsy treatment.