Fornal Casimir A, Martín-Cora Francisco J, Jacobs Barry L
Program in Neuroscience, Green Hall, Princeton University, Princeton, NJ 08544, USA.
Brain Res. 2006 Feb 9;1072(1):55-61. doi: 10.1016/j.brainres.2005.12.007. Epub 2006 Jan 17.
Single unit activity of presumed serotonergic neurons in the medulla [n. raphe obscurus (NRO) and pallidus (NRP)] or the mesencephalon [n. raphe dorsalis (DRN)] was recorded in adult male cats during prolonged treadmill locomotion. Treadmill speed was set at a moderate level (0.4 m/s) in order to induce long-duration locomotion. The typical time to "fatigue" (failure to keep pace, falling behind and reluctance to continue) was approximately 40 min in both groups, at which point cats typically displayed marked panting and vocalization. The activity of DRN neurons was unchanged from baseline during the locomotion trial and during the recovery phase. By contrast, the activity of NRO/NRP neurons decreased steadily across the locomotion trial, reaching a mean decrease of approximately 50% (during the first min after the treadmill was turned off). Full recovery of single unit activity to a level approximating the baseline discharge rate required 30-45 min. Possible mechanisms underlying these changes are discussed as is the role of serotonin and fatigue in human pathology.
在成年雄性猫长时间在跑步机上运动期间，记录了延髓中假定的5-羟色胺能神经元[中缝隐核（NRO）和苍白核（NRP）]或中脑[中缝背核（DRN）]的单单位活动。跑步机速度设定为中等水平（0.4米/秒），以诱导长时间运动。两组猫达到“疲劳”（无法跟上节奏、落后并不愿继续）的典型时间约为40分钟，此时猫通常会出现明显的气喘和鸣叫。在运动试验期间和恢复阶段，DRN神经元的活动与基线相比没有变化。相比之下，在整个运动试验过程中，NRO/NRP神经元的活动稳步下降，在跑步机停止后的第一分钟内平均下降约50%。单单位活动完全恢复到接近基线放电率的水平需要30-45分钟。讨论了这些变化的潜在机制以及5-羟色胺和疲劳在人类病理学中的作用。
