Blaha C D, Allen L F, Das S, Inglis W L, Latimer M P, Vincent S R, Winn P
Department of Psychology, University of British Columbia, Vancouver, Canada.
J Neurosci. 1996 Jan 15;16(2):714-22. doi: 10.1523/JNEUROSCI.16-02-00714.1996.
Microinjections of the cholinergic receptor agonist nicotine and the cholinesterase inhibitor neostigmine were made into the ventral tegmental area (VTA) of urethane-anesthetized rats, and dopamine (DA) efflux in the nucleus accumbens was measured using in vivo chronoamperometry. Dose-dependent increases in the chronoamperometric signals corresponding to increased DA efflux were observed in the nucleus accumbens of normal intact rats after cholinergic stimulation of the VTA. The source of the cholinergic input to the VTA was investigated by making excitotoxic lesions in either the laterodorsal tegmental nucleus (LDTg) or the pedunculopontine tegmental nucleus (PPTg). Compared with sham-operated control animals, which showed the same response as intact, nonlesioned rats, ibotenate lesions of the LDTg attenuated the stimulatory effects of intra-VTA neostigmine on DA efflux in the nucleus accumbens. In contrast, rats with ibotenate lesions of the PPTg showed normal nucleus accumbens DA eflux after intra-VTA injections of neostigmine. Such lesions in the PPTg attenuate DA efflux in the caudate-putamen stimulated by injections of neostigmine into the substantia nigra pars compacta (SNc). The present data show that cholinergic neurons in the LDTg, but not the PPTg, regulate the activity of DA-containing neurons in the VTA, which complements previous data showing that cholinergic neurons in the PPTg regulate DA-containing neurons in the SNc.
将胆碱能受体激动剂尼古丁和胆碱酯酶抑制剂新斯的明微量注射到经乌拉坦麻醉的大鼠腹侧被盖区（VTA），并使用体内计时电流法测量伏隔核中的多巴胺（DA）流出量。在对VTA进行胆碱能刺激后，正常完整大鼠的伏隔核中观察到与DA流出量增加相对应的计时电流信号呈剂量依赖性增加。通过在外侧背侧被盖核（LDTg）或脚桥被盖核（PPTg）中制造兴奋性毒性损伤来研究VTA的胆碱能输入来源。与假手术对照动物（其反应与完整未损伤大鼠相同）相比，LDTg的鹅膏蕈氨酸损伤减弱了VTA内新斯的明对伏隔核中DA流出的刺激作用。相反，PPTg的鹅膏蕈氨酸损伤大鼠在VTA内注射新斯的明后伏隔核DA流出正常。PPTg中的此类损伤减弱了向黑质致密部（SNc）注射新斯的明所刺激的尾状核 - 壳核中的DA流出。目前的数据表明，LDTg中的胆碱能神经元而非PPTg中的胆碱能神经元调节VTA中含DA神经元的活性，这补充了先前的数据，即PPTg中的胆碱能神经元调节SNc中含DA的神经元。
