Role of subthalamic nucleus in nigral control of epilepsy: a lesion and high frequency stimulation study in an animal model of generalized epilepsy.

The involvement of substantia nigra pars reticulata (SNr) in the control of generalized seizure in animal models has been demonstrated. SNr receives a major glutamatergic excitatory input from the subthalamic nucleus (STN) le ading to the hypothesis that STN inactivation could reproduce rite antiepil eptic effect of the Snr GAGAergic potentiation. Excitotoxic lesion and high frequency stimulation were applied onto the STN of Genetic Absence Epileps y Rats Si-om Strasbourg (GAERS). In the lesion experiment. 9 GAERS rats wer e bilaterally injected into the STN with 2 mg/side kainic acid. Compared to the control group (n = 5), cumulated and mean duration of seizures measure d on EEG recordings were significantly reduced (48 and 34% decrease respect ively) in the lesioned group. in the second experiment, HFS was performed i n 8 GAERS mts. When applied acutely, high frequency stimulation (130 Hz) su ppressed seizures with an intensity threshold, related to the proximity of the stimulating electrode to the STN. The antiepileptic intensity threshold appear to be slight inferior to dyskinesia-induced threshold Inactivation of STN by kainic acid lesion or high frequency stimulation induced a decrea se or a suppression of seizures in GAERS rats, suggesting the implication o f STN lit the control of generalized epilepsy.