Morin L P, Blanchard J
Department of Psychiatry, State University of New York, Stony Brook 11794.
Brain Res. 1991 Dec 6;566(1-2):186-92. doi: 10.1016/0006-8993(91)91697-y.
Depletion of brain serotonin by 5,7-dihydroxytryptamine (DHT) produces large changes in photic regulation of the hamster circadian running rhythm. This study documents the changes in daily wheelrunning caused by DHT lesions and their relationship to changes in photic conditions or food availability. Hamsters were given bilateral infusions of the selective neurotoxin during entrainment to a light-dark cycle (LD) of 14:10 h. At a later time, animals were transferred to constant light (LL) or dark (DD) for a prolonged period. Animals in DD were also subject to 3 days of food deprivation. Destruction of the serotonergic system does not change the amount of daily running in LD 14:10, but does alter the rate of running. Control animals respond to LL by greatly decreasing running compared to those with lesions. Food deprivation, a condition that greatly elevates running in control animals, is not nearly as effective in lesioned animals. The results suggest that serotonin-depleted hamsters have diminished responsiveness to environmental stimuli.
5,7-二羟基色胺（DHT）导致脑内血清素耗竭，会使仓鼠昼夜节律性跑步行为的光调节发生巨大变化。本研究记录了DHT损伤引起的每日转轮行为变化及其与光照条件或食物供应变化的关系。在使仓鼠适应14:10小时明暗循环（LD）的过程中，对其进行双侧选择性神经毒素注射。之后，将动物长期转移至持续光照（LL）或黑暗（DD）环境中。处于DD环境中的动物还会经历3天的食物剥夺。血清素能系统的破坏不会改变LD 14:10条件下的每日跑步量，但会改变跑步速率。与有损伤的动物相比，对照动物对LL的反应是大幅减少跑步量。食物剥夺这种能极大提高对照动物跑步量的情况，对有损伤的动物效果却不明显。结果表明，血清素耗竭的仓鼠对环境刺激的反应性降低。
