AIMTo study the characteristics of neural information encoding of the epileptic networks involved caudate-putamen(CPu) and the hippocampi induced by tetanization of the right CPu in rats.

METHODSExperiments were performed on 59 SD rats. Acute or chronic tetanization of the right CPu (ATRC or CTRC) (60Hz,0.4-0.6 mA, 2 s) was used to induce rat epilepsy.

RESULTS(1) The bursting or primary unit afterdischarges of single neurons were asymmetric in dual hippocampi induced by the ATRC. (2) Continuous sharp waves were observed in ipsilateral or contralateral CPu induced by the CTRC. The oscillatory network seizures with phase shift appeared between two sharp waves in ipsilateral CPu. The frequency of oscillatory waves was negatively correlated with the time and fluctuated from 70 Hz to 110 Hz, then to 35 Hz, and finally to 30 Hz. (3) In the contralateral side primary network after discharges in the CPu were induced by the CTRC. Therefore, the characteristic primary network afterdischarges could be shifted from the CPu or to the HPC, but amplified. On the other hand, HPC sharp waves could be depressed when the CPu network seizures occurred.

CONCLUSIONThe reestablishment of CPu-hippocampal epileptic networks could be transhemispherically promoted by over-activation of the right CPu network, in which bilateral hippocampal neuronal network and CPu neural network were involved in some particular pathophysiological information encoding.