脑室内注射蝇蕈醇或γ-氨基丁酸对猪操作性进食的影响。

Effects of intracerebroventricular injection of muscimol or GABA on operant feeding in pigs.

作者信息

Baldwin B A, Ebenezer I S, De La Riva C

机构信息

AFRC Institute of Animal Physiology and Genetics Research, Cambridge Research Station, Babraham, UK.

出版信息

Physiol Behav. 1990 Sep;48(3):417-21. doi: 10.1016/0031-9384(90)90337-4.

DOI:10.1016/0031-9384(90)90337-4

PMID:2176292

Abstract

Young pigs were prepared with lateral intracerebroventricular (ICV) cannulae. They were housed individually in cages fitted with operant panels and could obtain food and water ad lib. The GABA-A receptor agonist muscimol (25-200 nmol) ICV produced an increase in food intake in which the dose-response relation was most obvious 30-60 min after dosing. The 25-nmol dose had no effect on feeding. However, muscimol (50 nmol) caused a significant increase in feeding (p less than 0.01) during the first 30 min after injection, while the 100- and 200-nmol doses increased food intake (p less than 0.01) during the first 60 min. The effect of muscimol (100 nmol) on food intake was completely abolished by the simultaneous administration of the GABA-A receptor antagonist bicuculline (100 nmol). GABA (40-1600 nmol) ICV also produced a dose-related increase in food intake (p less than 0.01) in the 15 min after injection. Only doses of 800 nmol and above were effective. The effects of GABA (1600 nmol) were completely abolished by the simultaneous administration of bicuculline (50 nmol). Neither muscimol nor GABA influenced food intake for the 24-hr time period or water intake during any time period. The results indicate that stimulation of central GABA-A receptors induces operant feeding in the satiated pig.

摘要

幼猪通过侧脑室（ICV）插管进行制备。它们被单独饲养在装有操作面板的笼子里，可以自由获取食物和水。GABA-A受体激动剂蝇蕈醇（25 - 200 nmol）经侧脑室注射后会使食物摄入量增加，给药后30 - 60分钟剂量 - 反应关系最为明显。25 nmol剂量对进食无影响。然而，蝇蕈醇（50 nmol）在注射后的前30分钟内导致进食量显著增加（p < 0.01），而100和200 nmol剂量在最初60分钟内增加了食物摄入量（p < 0.01）。同时给予GABA-A受体拮抗剂荷包牡丹碱（100 nmol）可完全消除蝇蕈醇（100 nmol）对食物摄入的影响。GABA（40 - 1600 nmol）经侧脑室注射后在注射后15分钟内也产生了与剂量相关的食物摄入量增加（p < 0.01）。只有800 nmol及以上剂量才有效。同时给予荷包牡丹碱（50 nmol）可完全消除GABA（1600 nmol）的作用。蝇蕈醇和GABA在24小时时间段内均不影响食物摄入，在任何时间段内也不影响水的摄入。结果表明，刺激中枢GABA-A受体可诱导饱腹状态下的幼猪自主进食。