蓝斑核损伤对迷走神经刺激抗癫癎效应的影响

目的：探讨刺激迷走神经（ＶＮＳ）的抗癫癎作用与蓝斑核（ＬＣ）的相互关系。　方法：立体定向下注射６－羟多巴胺（６－ＯＨＤＡ）毁损大鼠双侧ＬＣ，２ 周后腹腔注射戊四氮（ＰＴＺ），８０ ｍ ｇ／ｋｇ 体重致癎，然后观察刺激迷走神经的抗癫癎效应，同时测定大鼠大脑皮质及海马中去甲肾上腺素（ＮＡ）水平。　结果：ＶＮＳ明显减轻ＰＴＺ致癎大鼠癫癎发作的严重程度，但对蓝斑核毁损的大鼠抗癫癎作用明显减弱，同时蓝斑核毁损后皮质及海马内ＮＡ含量较对照组明显下降。　结论：实验证明蓝斑核参与ＶＮＳ的抗癫癎作用，ＶＮＳ可能通过增加脑内ＮＡ 的释放而发挥抗癫癎效应。这一结论提示，拟去甲肾上腺素类药物可能有增强ＶＮＳ的抗癫癎作用。

The role of locus coeruleus in the antiepileptic effect of vagus nerve stimulation

Objectives: To explore the relationship between the anti epileptic effects of vagus nerve stimulation (VNS) and the locus coeruleus (LC). Methods: Rats were chronically depleted of noradrenaline (NA) by a bilateral stereotactic infusion of 6 hydroxydopamine (6 OHDA) into the LC. Two weeks later, they were treated with injection into the peritoneum of pentylenetetrazol (PTZ). The antiepileptic effects of VNS were observed and the NA levels of cortex and hippocampus were examined. Results: VNS can significantly reduce the seizure severities of control rats, but had no effect on the rats with chronic LC Lesions. The NA levels in the rats with chronic LC lesions were significantly lower than in the control rats. Conclusions: The LC is involved in the circuitry necessary for the anticonvulsant effects of VNS. Seizure prevention by VNS may therefore depend on the release of NA, a neurotransmitter that has anticonvulsant effects. These data suggest that noradrenergic agonists might enhance VNS induced seizure suppression.