强直电刺激右侧尾壳核对大鼠海马、中部颞叶新皮质电图的影响

EFFECTS OF TETANIZATION OF THE RIGHT CAUDATE-PUTAMEN ON THE DEPTH ELECTROGRAPHS IN THE HIPPOCAMPUS OR MEDIAL TEMPORAL LOBE NEOCORTEX ELECTROGRAPHS IN RATS

目的 :探讨尾壳核 (caudate putamen ,CPu) 海马 (hippocampus,HPC) 中部颞叶新皮质 (Medialtemporallobeneocortex ,MTNC)通路在癫痫相关性病理神经网络重建中的作用。方法 :4 5只SD大鼠。用不锈钢双极同芯电极记录右侧HPC、右侧MTNC、左、右侧HPC、右侧HPC和右侧MTNC深部电图 ,重复强直电刺激 (6 0Hz ,2s,0 .4～0 .6mA)大鼠右侧CPu 10次 ,每次刺激间隔时间约 10min ,观察上述脑区深部电图的改变。结果 :强直电刺激右侧CPu可以诱发植入电极同侧或双侧HPC出现原发性后放和继发性电图癫痫样点燃效应 ,也可以表现为HPC深部电图脑电波出现压抑 反弹 癫痫样点燃发作 ;诱发同侧HPC与MTNC出现部分同步性阵发癫痫样电活动 ;腹腔注射东莨菪碱 (0 .0 5mg/kg)后 ,重复上述电刺激右侧CPu实验 ,可以诱发双侧HPC电图出现 3Hz慢波电振荡长时程增强现象 ,也可以诱发同侧HPC与MTNC出现完全同步的阵发性癫痫样电活动。结论 :过度激活CPu功能可以促进CPu HPC MTNC通路癫痫相关性病理生理性神经网络重新的建立 ,该效应累及对侧大脑半球 。

Aim: To study the role of the caudate putamen(CPu) hippocampus(HPC) medial temporal lobe neocortex(MTNC) neural pathway in re establishment of pathophysiological neural networks related to epileptogenesis. Methods: Experiments were performed under anaesthesia on 45 SD rats. The right HPC, the right MTNC, bilateral HPC, the right HPC and the right MTNC depth electrographs were recorded with bipolar concentric electrodes. Tetanization (60 Hz,2 s,0.4～0.6 mA) of the right CPu or of the right HPC trains were used to establish acute rat epilepsy model. These depth electrographs were detected before or after tetani were delivered about 10 times at 10 min intervals. Results: Tetanization of the right CPu induced (1)primary afterdischarges and unilateral or bilateral HPC electrographic afterdischargs and kindling effect or inhibition rebound kindling effect were induced by repetitive tetani into the right CPu. (2)After injection of scopolamine (0.05 mg/kg i.p.), 3 Hz slow oscillations in HPC electrographs exhibited long term potentiation followed by repecitive tetani into the right CPu.(3) After administration of scopolamine (i.p) electrographic oscillations at 3Hz with synaptic modification in bilateral HPC were induced and epileptiform activities in the RHPC were synchronized with those in the RMTNC. Conclusion: pathophysiological neural networks from the Cpu into the HPC might be reestablished by overactivation of the right CPu, in which two hemispheres are involved while temporal lobe epileptogenesis was facilitated.