电刺激中央中核、中央外侧核对猫丘脑后核群内脏痛放电的影响

目的：研究中央中核、中央外侧核在痛觉调制中的作用及作用机理。方法：以电刺激内脏大神经在丘脑后核群诱发的单位放电作为内脏痛指标，应用细胞外玻璃微电极记录技术及条件-检验刺激技术，研究电刺激中央中核、中央外侧核对内脏痛放电的影响。结果：中央中核、中央外侧核对丘脑后核群内脏痛放电主要表现为抑制作用，抑制作用形式可分为即时抑制、延迟抑制及持续抑制，纳洛酮可拮抗中央中核的抑制作用。结论：中央中核、中央外侧核参与内脏痛的调制，主要为抑制内脏痛中央中核的抑制作用强于中央外侧核的抑制作用。内源性吗啡样物质参与中央中核对该内脏痛的抑制过程。

Effects of Electrically Stimulating Centromedian Nucleus and Central Lateral Nucleus on Visceral Pain Discharges in Posterior Group of Thalamic Nuclei of Cats

Objective: Our aim was to study the effects of centromedian nucleus(CM) and central lateral nucleus(CL)on pain and their mechanisms. Methods:As an index of visceral pain,the discharges of the neurons in the posterior group of thalamic nuclei(PO),evoked by stimulating greater splanchnic nerve(GSN)in 61 cats were investigated extracellularly.The effects of CM and CL on the unit discharges were also studied with test-conditioning stimulation techniques.Results:We stimulated CM or CL (conditioning stimulus)electrically The neuron discharges in PO,caused by excitation of GSN(test stimulus),were mainly depressed. The inhibitory forms of CM or CL could be classified into 3 kinds:prompt,delayed, and continued inhibition. These inhibitions of CM were antagonized by Naloxone.Conclusion:The CM and CL were involved in the regulation of visceral pain,mainly in analgesia of visceral pain. The inhibitory effect of CM were stronger than that of CL,and endogenous opiate-like substances were involved in the CM-induced inhibitory process.