丘脑前核在三叉神经电刺激减轻癫痫发作和海马神经元损伤中的作用

摘要

[ ABSTRACT] AIM: To investigate the role of anterior thalamic nucleus in trigeminal nerve electrostimulation ( TNS)-induced effects on seizures and hippocampal damage.METHODS: The rats were intraperitoneally injected with pilocarpine to induce chronic epilepsy, and then received sham treatment, TNS treatment and TNS treatment after stereotac-tic lesion to the anterior thalamic nucleus.The TNS treatment lasted for 1 month in each group.Another injection of pilo-carpine was conducted to induce seizures, and the severity and duration of seizures were quantitatively evaluated.TUNEL, Fluoro-Jade B ( FJB) and Nissl staining were applied to determine in situ apoptosis, neuronal degeneration and neuron loss in the hippocampal CA1 area respectively.RESULTS:Compared with TNS group, TNS treatment after stereotactic lesion to the anterior thalamic nucleus significantly increased the severity and duration of seizures (P<0.05), and the numbers of TUNEL positive cells, FJB positive cells and lost neurons in the hippocampal CA1 area (P<0.01).CONCLUSION:Anterior thalamic nucleus plays a role in TNS-induced reduction of seizures and hippocampal damage.The mechanisms might be due to the chronically activation of the cortex through anterior thalamic nucleus pathway induced by TNS, resulting in the down-regulation of neuronal excitatory susceptibility.%目的：探讨丘脑前核在三叉神经电刺激（ TNS）减轻癫痫发作和海马神经元损伤中的作用。方法：大鼠经腹腔注射匹罗卡品建立慢性癫痫模型，模型大鼠分别给予假刺激、三叉神经电刺激和立体定向毁损丘脑前核预处理后三叉神经电刺激1月，再次诱导癫痫发作，观察大鼠的癫痫行为表现，并通过TUNEL、Fluoro-Jade B （ FJB）染色和Nissl染色观察大鼠海马CA1区神经元的凋亡、变性及脱失情况。结果：与未经毁损丘脑前核的TNS处理大鼠相比，毁损丘脑前核后的TNS处理大鼠癫痫发作的级别分数及持续时间明显增加（ P＜0.05），且毁损丘脑前核后的TNS处理大鼠癫痫发作后海马CA1区TUNEL、FJB阳性细胞及细胞的脱失较TNS组显著增加（ P＜0.01）。结论：毁损丘脑前核后，TNS减轻癫痫发作及海马神经元损伤的作用被显著降低，表明丘脑前核在TNS抗癫痫中发挥一定的作用；潜在机制可能是TNS通过丘脑前核慢性激活丘脑与大脑皮层的纤维联系，使海马神经元兴奋性易感性改变。