Hernandez L L, Valentine J D, Powell D A
William Jennings Bryan Dorn Veterans Hospital, Columbia, South Carolina 29201.
Behav Neurosci. 1991 Jun;105(3):431-42. doi: 10.1037//0735-7044.105.3.431.
Intravenous naloxone enhanced, and D-Ala2-Met-enkephalinamide (DALA) impaired, Pavlovian conditioned heart rate discrimination in rabbits (Oryctolagus cuniculus) during initial training trials, compared with saline; naloxone also delayed subsequent extinction of the discrimination. These effects of the opioid treatments on discrimination were abolished by parasagittal knife-cut lesions in the sublenticular substantia innominata that did not, themselves, impair discrimination. Both naloxone and DALA decreased the magnitude and altered the topography of bradycardiac conditioned responses, and the lesions also abolished these effects of the opioid treatments, but they did not alter the effect of naloxone to decrease bradycardiac orienting response magnitude. These findings suggest that fibers in the sublenticular area mediate specifically the effects of systemic opioids on associative functions during Pavlovian cardiac conditioning and extinction.
与生理盐水相比，在最初的训练试验中，静脉注射纳洛酮增强了家兔（穴兔）的巴甫洛夫条件性心率辨别能力，而D - Ala2 - Met - 脑啡肽酰胺（DALA）则损害了这种能力；纳洛酮还延迟了随后辨别能力的消退。在不损害辨别能力的情况下，经矢状旁刀切割豆状核下无名质的病变消除了阿片类药物治疗对辨别的这些影响。纳洛酮和DALA均降低了心动过缓条件反应的幅度并改变了其波形，并且这些病变也消除了阿片类药物治疗的这些影响，但它们并未改变纳洛酮降低心动过缓定向反应幅度的作用。这些发现表明，豆状核下区域的纤维在巴甫洛夫心脏条件反射和消退过程中特异性地介导了全身阿片类药物对联想功能的影响。
