Thornton E W, Bradbury G E, Wickens A P, Mottram D R, McClelland R
University of Liverpool, England, United Kingdom.
Behav Neural Biol. 1990 Mar;53(2):291-7. doi: 10.1016/0163-1047(90)90560-s.
The anatomical connections of the habenula complex indicate it provides a relay between limbic forebrain and midbrain. Somewhat paradoxically, consequences of nonspecific lesion of the habenula are ambiguous with little change in basic response evident within simple behavioral paradigms. However, the potential functional importance for this relay has more recently been indicated by the demonstration of deficits in the ability of lesioned animals to alter behavior appropriate to both internal and external stimuli in more demanding behavioral tasks. Doubts concerning the importance of the habenula remain because of the large number of descending fibers of passage through the habenula. To provide more substantive evidence, 6-hydroxydopamine was injected into the habenula of rats to provide more limited lesion of catecholaminergic terminals. Animals were subsequently trained on an operant DRL 20-s schedule for which deficits have been reported following nonspecific lesion of the habenula. Lesioned animals showed a tendency to overrespond and were significantly less efficient on the schedule with decreased number of reinforcements received relative to controls. While the neurotoxic lesion procedure used does not differentiate noradrenergic and dopaminergic damage, the importance of intact catecholaminergic systems within the habenula for effective DRL acquisition is consistent with the suggested importance of the habenula for feedback regulation of dopamine within the ventral tegmental area through ascending dopamine fibers to the habenula.
缰核复合体的解剖学连接表明它在边缘前脑和中脑之间起到中继作用。 somewhat paradoxically（此处英文有误，正确为“Somewhat paradoxically”，意为“ somewhat paradoxically”），缰核非特异性损伤的后果并不明确，在简单行为范式中基本反应几乎没有明显变化。然而，最近通过证明损伤动物在更具挑战性的行为任务中改变适合内部和外部刺激的行为能力存在缺陷，表明了这种中继的潜在功能重要性。由于大量下行纤维穿过缰核，关于缰核重要性的疑问仍然存在。为了提供更确凿的证据，将6-羟基多巴胺注入大鼠的缰核，以对儿茶酚胺能终末进行更有限的损伤。随后，动物接受操作性DRL 20秒程序的训练，此前有报道称缰核非特异性损伤后会出现缺陷。损伤动物表现出过度反应的倾向，并且在该程序中效率显著降低，相对于对照组，获得的强化次数减少。虽然所使用的神经毒性损伤程序无法区分去甲肾上腺素能和多巴胺能损伤，但缰核内完整的儿茶酚胺能系统对于有效获得DRL的重要性与缰核通过多巴胺上行纤维至缰核对腹侧被盖区内多巴胺进行反馈调节的重要性相一致。
