Gold L H, Swerdlow N R, Koob G F
Department of Basic and Clinical Research Scripps Clinic, La Jolla, California 92037.
Behav Neurosci. 1988 Aug;102(4):544-52. doi: 10.1037//0735-7044.102.4.544.
Daily administration of psychomotor stimulants in a distinctive environment can impart on the environment stimulantlike properties. Rats injected with amphetamine (0.75 mg/kg, sc) daily for 5 days exhibited a robust unconditioned locomotor response, measured in photocell cages, and showed a conditioned locomotor response when treated with saline on the 6th day. This conditioned locomotor response was found to be significantly attenuated by 6-hydroxydopamine (6-OHDA) lesions of the nucleus accumbens when the lesion was made either pre- or postconditioning. Similarly, although rats with 6-OHDA lesions of the nucleus accumbens exhibited a robust supersensitive unconditioned locomotor hyperactivity in response to apomorphine (0.1 mg/kg, sc), they did not show a conditioned response on the test day. These results suggest that the mesolimbic dopamine system may be responsible for both the unconditioned and conditioned locomotor responses to psychomotor stimulant drugs. Further, conditioned locomotion depends on a critical interaction between the physiological release of presynaptic dopamine and occupation of postsynaptic receptors.
在独特环境中每日给予精神运动性兴奋剂可使该环境具有类似兴奋剂的特性。连续5天每天皮下注射苯丙胺（0.75毫克/千克）的大鼠，在光电笼中测量时表现出强烈的非条件性运动反应，并且在第6天用生理盐水处理时表现出条件性运动反应。当在条件化之前或之后对伏隔核进行6-羟基多巴胺（6-OHDA）损伤时，发现这种条件性运动反应会显著减弱。同样，尽管伏隔核有6-OHDA损伤的大鼠对阿扑吗啡（0.1毫克/千克，皮下注射）表现出强烈的超敏非条件性运动亢进，但它们在测试日并未表现出条件反应。这些结果表明，中脑边缘多巴胺系统可能负责对精神运动性兴奋药物的非条件性和条件性运动反应。此外，条件性运动依赖于突触前多巴胺的生理释放与突触后受体占据之间的关键相互作用。
