Sañudo-Peña M C, Walker J M
Schrier Research Laboratory, Department of Psychology, Brown University, Providence, Rhode Island 02912, USA.
J Neurophysiol. 1997 Mar;77(3):1635-8. doi: 10.1152/jn.1997.77.3.1635.
The effect of cannabinoids on the excitatory input to the substantia nigra reticulata (SNr) from the subthalamic nucleus was explored. For this purpose a knife cut was performed rostral to the subthalamic nucleus to isolate the subthalamic nucleus and the SNr from the striatum, a major source of cannabinoid receptors to the SNr. The data showed that the cannabinoid agonist WIN55,212-2 blocked the increase in the firing rate of SNr neurons induced by stimulation of the subthalamic nucleus with bicuculline. Furthermore, the cannabinoid antagonist SR141716A antagonized the effect of the cannabinoid agonist. This study showed that cannabinoids regulate not only the striatonigral pathway, as previously reported, but also the subthalamonigral pathway. The opposite influences of these two inputs to the SNr, inhibitory and excitatory respectively, suggest that endogenous cannabinoids play a major role in the physiological regulation of the SNr.
研究了大麻素对丘脑底核向黑质网状部（SNr）兴奋性输入的影响。为此，在丘脑底核前方进行了切割，以将丘脑底核和SNr与纹状体分离，纹状体是SNr大麻素受体的主要来源。数据显示，大麻素激动剂WIN55,212-2可阻断荷包牡丹碱刺激丘脑底核诱导的SNr神经元放电频率增加。此外，大麻素拮抗剂SR141716A可拮抗大麻素激动剂的作用。该研究表明，大麻素不仅如先前报道的那样调节纹状体黑质通路，还调节丘脑底核黑质通路。这两种对SNr的输入分别具有抑制和兴奋作用，其相反影响表明内源性大麻素在SNr的生理调节中起主要作用。
