蓝斑核在针刺影响海马锥体细胞自发放电中的作用

<正> 不少实验报道,海马参与针刺镇痛,而针刺既可影响痛感觉,又可影响痛情绪,其中尤对病情绪反应的压抑较强,这可能与海马的机能有关。电生理实验表明,刺激蓝斑和中缝核均显著改变海马细胞放电形式,我们也曾看到,电针、刺激蓝斑及中缝背核对海马锥体细胞均有明显抑制效应,且形态学证明脑内存在从中缝核及蓝斑核投射到海马的神经通路。中缝核与蓝斑核在针刺镇痛中似存在相互拮抗的效应,而中缝核与蓝斑核之间也存在相互抑制性控制。本文试图分别通过电刺激及损毁蓝斑,以及应用某些药物的方法,来观察该核团在针刺影响海马锥体细胞自发放电活动过程中所起的作用。

ROLE OF LOCUS COERULEUS IN EFFECTS OF ELECTROACUPUNCTURE ON HIPPOCAMPAL PYRAMIDAI CELLS SPONTANEOUS FIRING IN THE RAT

The effects of electroacupuncture on dorsal hippocampal pyramidal ce- lls spontaneous firing under the condition of electrical stimulation or le- sion of locus coeruleus (LC) were investigated in urethane anesthetized ra- ts. The spontaneous firing of dorsal hippocampal cells was mainly inhibi- ted when electroacupuncting ‘Jiaji’points. Similar inhibitory effects of electrical stimulatinn on LC were observed. The effects of electroacupun- cture were not appeared after lesions of bilateral LC, or partially blocke- d after iv phentolamine (an a-receptor antagonist), and completely blocke- d after yohimbine (an a_2-antagonist). Clonidine (an a_2-receptor agonist) was ineffective in this regard. These results suggest that LC may be an important links in effect of electroacupuncture on pyramidal cells firing of hippocampus. It also showed that the effect of electroacupuncture seemed to be mediated by a-receptor, especially that by a_2 receptor.