Bechara A, Martin G M, Pridgar A, van der Kooy D
Department of Anatomy, University of Toronto, Ontario, Canada.
Behav Neurosci. 1993 Feb;107(1):147-60. doi: 10.1037//0735-7044.107.1.147.
Bilateral ibotenic acid lesions of the lateral, but not the medial, parabrachial nucleus (PBN) blocked conditioned taste aversion (CTA) induced by morphine but not conditioned place preference induced by morphine. The same lateral PBN lesions also blocked conditioned place aversion produced by low intraperitoneal doses of morphine (shown to produce aversion, instead of preference, due to a restricted action on gut opiate receptors). Lateral PBN lesions did not block CTA produced by LiCl. Cerebral peduncle lesions that destroyed the direct descending projections from the visceral cortex to the PBN did not block CTA induced by morphine, nor did ibotenic acid lesions of the tegmental pedunculopontine nuclei (shown to block place preference produced by even high morphine doses). It is suggested that the lateral PBN is a critical link in the neural pathway carrying the aversive motivational effects of opiates from the gut into the central nervous system, independent of the neural pathway carrying the rewarding motivational effects of morphine.
损毁臂旁外侧核而非内侧核的双侧鹅膏蕈氨酸损伤阻断了吗啡诱导的条件性味觉厌恶（CTA），但未阻断吗啡诱导的条件性位置偏爱。同样的外侧臂旁核损伤也阻断了低剂量腹腔注射吗啡产生的条件性位置厌恶（由于对肠道阿片受体的作用受限，已证明会产生厌恶而非偏爱）。外侧臂旁核损伤并未阻断氯化锂产生的CTA。损毁从内脏皮质到臂旁核的直接下行投射的脑桥脚损伤并未阻断吗啡诱导的CTA，被盖脚桥被盖核的鹅膏蕈氨酸损伤（已证明即使是高剂量吗啡产生的位置偏爱也能阻断）也未阻断。提示外侧臂旁核是将阿片类药物从肠道进入中枢神经系统的厌恶动机效应传递的神经通路中的关键环节，独立于携带吗啡奖赏动机效应的神经通路。
