Hitchcott P K, Phillips G D
Department of Psychology, University of York, Heslington, UK.
Psychopharmacology (Berl). 1997 May;131(2):187-95. doi: 10.1007/s002130050283.
Limbic innervation of the nucleus accumbens via the ventral subiculum/hippocampus and basolateral area of the amygdala has been shown to determine dissociable aspects of behaviour controlled by stimuli associated with natural rewards. However, the respective contributions of the ventral subiculum and amygdala to behaviour governed by drug-associated stimuli remain to be determined. Experiments consisted of two phases: drug-stimulus training, and subsequent stimulus-only testing. Initial training sessions were of two alternating forms. During drug sessions, responding upon one lever resulted in an infusion of 1 microgram d-amphetamine into the nucleus accumbens, whilst during saline sessions d-amphetamine was replaced with saline. Each infusion (drug or saline) was preceded with either a light, or tone. Responding upon a control lever had no programmed consequences. Following training, the levers were retracted, and instead two novel vertical bars were extended from the chamber ceiling. Movement of one bar produced the drug-associated stimulus, whilst the alternative bar produced the saline-associated stimulus. Infusions of the AMPA receptor antagonist CNQX into the ventral subiculum or basolateral area of the amygdala (0, 0.2, 2.0 nmol) were made immediately before the start of each session. Intra-basolateral area of the amygdala CNQX reduced responding upon the drug-associated stimulus bar, but at the same time increased responding upon the saline-associated stimulus bar. By contrast, intra-ventral subiculum CNQX reduced drug-associated stimulus responding selectively. Neither manipulation affected levels of activity within the operant chamber extraneous to the bar-pushing response. Hence, the basolateral area of the amygdala appeared to have determined the degree of discriminative control exerted over behaviour by the drug-associated stimulus, whilst the ventral subiculum is suggested to have determined the efficacy of the conditioned reward.
已表明，通过腹侧下托/海马体和杏仁核基底外侧区，伏隔核的边缘神经支配决定了由与自然奖励相关的刺激所控制行为的可分离方面。然而，腹侧下托和杏仁核对与药物相关刺激所支配行为的各自贡献仍有待确定。实验包括两个阶段：药物刺激训练和随后的仅刺激测试。初始训练课程有两种交替形式。在药物课程期间，按压一个杠杆会导致向伏隔核注入1微克右旋苯丙胺，而在生理盐水课程期间，右旋苯丙胺被生理盐水取代。每次注入（药物或生理盐水）之前，会伴随有光或音调。按压控制杠杆没有设定的结果。训练后，杠杆缩回，取而代之的是从实验箱天花板伸出两根新的垂直杆。移动一根杆会产生与药物相关的刺激，而另一根杆会产生与生理盐水相关的刺激。在每次课程开始前，立即向腹侧下托或杏仁核基底外侧区注入AMPA受体拮抗剂CNQX（0、0.2、2.0纳摩尔）。杏仁核基底外侧区内注入CNQX会减少对与药物相关刺激杆的反应，但同时会增加对与生理盐水相关刺激杆的反应。相比之下，腹侧下托内注入CNQX会选择性地减少与药物相关刺激的反应。两种操作均未影响推压杆反应之外的操作箱内的活动水平。因此，杏仁核基底外侧区似乎决定了与药物相关刺激对行为施加的辨别控制程度，而腹侧下托则被认为决定了条件性奖励的效果。
