Purpose: Interictal intervals in pilocarpine-induced chronic epilepsy are characterized by apparent normal electrographic activity and longer sleep periods or drowsiness or both. Sparse information exists concerning the neural network activity during these seizure-free intervals. In our research, a [14C]2-deoxy-D-glucose (2DG) autoradiographic technique was used to investigate interictal changes in the metabolism of the epileptic rat brain.
Methods: Epileptic rats were monitored by video-EEG for approximately 120 days, with [14C]2DG injected after a seizure-free interval of > or = 24 h.
Results: Autoradiographic analysis revealed an increase in glucose utilization by several brain regions; the most consistent increase was found in the lateral posterior thalamic nucleus and pretectal region.
Conclusions: These findings suggest that the lateral posterior thalamic nucleus and the pretectal region may be involved in cerebral circuits inhibiting epileptic activity during interictal intervals.