Fady J C, Jamon M, Clarac F
C.N.R.S.-NBM, Marseille, France.
Brain Res Dev Brain Res. 1998 Jun 15;108(1-2):111-23. doi: 10.1016/s0165-3806(98)00040-6.
Locomotor-like rhythmic movements without postural constraints were elicited in newborn rats aged from a few hours to five days, using an olfactory stimulus provided by bedding materials. The rats were held in a sling with the front and the hind legs hanging on each side. The step frequency increased between postnatal days 0 and 4 (P0-P4); the step period was around 1 s at P0 and decreased during the following days. This decrease was larger in the forelimbs (650 ms at P4) than in the hindlimbs (750 ms at P4) and was mainly due to a decrease in stance duration. Both ipsilateral and contralateral legs moved in an alternating pattern. Analysis of the regulation of this pattern when a 1:1 or a 1:2 inter-leg coordination (with double steps) occurred showed that both anterior and posterior locomotion pattern generators were coupled very early. Results are discussed in relation to the locomotor activities studied at this early stage of life in other behavioral situations (swimming and air stepping), and in relation to fictive locomotion induced in vitro.
利用垫料提供的嗅觉刺激，在出生几小时至五天的新生大鼠中诱发了不受姿势限制的类似运动的节律性运动。大鼠被置于吊带中，前腿和后腿分别垂在两侧。在出生后第0天至第4天（P0 - P4）步频增加；P0时步周期约为1秒，在随后几天缩短。前肢的这种缩短幅度（P4时为650毫秒）大于后肢（P4时为750毫秒），主要是由于站立持续时间缩短。同侧和对侧腿均以交替模式运动。当出现1:1或1:2的腿间协调（双步）时，对这种模式的调节分析表明，前后运动模式发生器很早就相互耦合。本文结合在生命这个早期阶段其他行为情境（游泳和空中踏步）中研究的运动活动，以及体外诱发的虚拟运动，对结果进行了讨论。
