Fanselow M S, Calcagnetti D J, Helmstetter F J
Psychology Department, University of California, Los Angeles 90024.
Behav Neurosci. 1989 Jun;103(3):663-72. doi: 10.1037//0735-7044.103.3.663.
MR2266 (MR), an opioid antagonist that binds to kappa and mu receptors, was examined for its ability to influence the aversively motivated behaviors conditioned by electric shock and the drinking induced by water deprivation or the availability of a palatable saccharin/glucose solution. The intraperitoneal (ip) and intracerebroventricular (icv) administration routes were contrasted. After both ip and icv administration, MR was able to reverse conditional analgesia as measured by the formalin test. MR enhanced the Pavlovian conditional freezing response when administered icv prior to shock exposure but reduced freezing if given ip prior to shock. A related benzomorphan-derived opioid antagonist, MR1452, also reduced freezing when given ip prior to shock. MR2266 was a potent antidipsogenic agent when administered ip but had no such effect when administered icv. It is concluded that separable opioid systems are involved in the modulation of appetitively and aversively motivated behaviors.
MR2266（MR）是一种与κ和μ受体结合的阿片类拮抗剂，研究了其影响电击诱发的厌恶动机行为以及缺水或可获得美味糖精/葡萄糖溶液诱导的饮水行为的能力。对比了腹腔内（ip）和脑室内（icv）给药途径。腹腔内和脑室内给药后，MR均能逆转福尔马林试验所测的条件性镇痛。在电击暴露前脑室内给药时，MR增强了巴甫洛夫条件性僵住反应，但在电击前腹腔内给药则降低了僵住反应。一种相关的苯并吗啡烷衍生的阿片类拮抗剂MR1452，在电击前腹腔内给药时也能降低僵住反应。MR2266腹腔内给药时是一种有效的抗渴剂，但脑室内给药时则无此作用。得出的结论是，可分离的阿片系统参与了对食欲和厌恶动机行为的调节。
