Fukuda M, Ono T, Nakamura K, Tamura R
Department of Physiology, Faculty of Medicine, Toyama Medical and Pharmaceutical University, Japan.
Brain Res Bull. 1990 Jul;25(1):109-14. doi: 10.1016/0361-9230(90)90260-7.
Unit activity in the rat lateral hypothalamus (LHA) was recorded during discrimination learning of cue tone stimuli (CTS). CTS+ predicted reward (glucose or intracranial self-stimulation); CTS- predicted aversion (electric shock or tail pinch); and all behavior responses were by the same act, licking. Roles of the LHA dopaminergic and cholinergic systems in CTS learning were investigated by electrophoretic application of dopamine (DA) and acetylcholine (ACh), and their antagonists. The CTS+, the predicted reward and DA, all had similar effects (inhibition) on many LHA neurons; and these were all opposite to the effects (excitation) of CTS-, the predicted aversion, and ACh. Neural responses to CTS+ were blocked by spiperone, and responses to CTS- were blocked by atropine. Sensitivity of LHA neurons to DA was reduced by extinction of CTS+ learning for reward, and sensitivity to ACh was reduced by CTS- learning for aversion. The data suggest that afferent DA and ACh inputs to LHA neurons are essential for plastic CTS+ and CTS- learning.
在大鼠辨别线索音刺激（CTS）的学习过程中，记录其外侧下丘脑（LHA）的单位活动。CTS+预示着奖励（葡萄糖或颅内自我刺激）；CTS-预示着厌恶（电击或夹尾）；所有行为反应均为舔舐这一相同动作。通过电泳施加多巴胺（DA）、乙酰胆碱（ACh）及其拮抗剂，研究了LHA多巴胺能和胆碱能系统在CTS学习中的作用。CTS+、预示的奖励和DA，对许多LHA神经元均有相似作用（抑制）；而这些作用均与CTS-、预示的厌恶和ACh的作用（兴奋）相反。对CTS+的神经反应被螺哌隆阻断，对CTS-的反应被阿托品阻断。通过消除对奖励的CTS+学习，LHA神经元对DA的敏感性降低；通过对厌恶的CTS-学习，对ACh的敏感性降低。数据表明，LHA神经元的传入DA和ACh输入对于可塑性CTS+和CTS-学习至关重要。
