Suster Maximiliano L, Bate Michael
Department of Zoology, University of Cambridge, UK.
Nature. 2002 Mar 14;416(6877):174-8. doi: 10.1038/416174a.
Locomotion depends on the integration of sensory information with the activity of central circuitry, which generates patterned discharges in motor nerves to appropriate muscles. Isolated central networks generate fictive locomotor rhythms (recorded in the absence of movement), indicating that the fundamental pattern of motor output depends on the intrinsic connectivity and electrical properties of these central circuits. Sensory inputs are required to modify the pattern of motor activity in response to the actual circumstances of real movement. A central issue for our understanding of how locomotor circuits are specified and assembled is the extent to which sensory inputs are required as such systems develop. Here we describe the effects of eliminating sensory function and structure on the development of the peristaltic motor pattern of Drosophila embryos and larvae. We infer that the circuitry for peristaltic crawling develops in the complete absence of sensory input; however, the integration of this circuitry into actual patterns of locomotion requires additional information from the sensory system. In the absence of sensory inputs, the polarity of movement is deranged, and backward peristaltic waves predominate at the expense of forward peristalsis.
运动依赖于感觉信息与中枢神经回路活动的整合，中枢神经回路会在运动神经中向适当的肌肉产生有规律的放电。孤立的中枢网络会产生虚构的运动节律（在没有运动的情况下记录到），这表明运动输出的基本模式取决于这些中枢回路的内在连接性和电特性。感觉输入是为了根据实际运动情况来改变运动活动模式所必需的。对于我们理解运动回路是如何被指定和组装的一个核心问题是，在这些系统发育过程中，感觉输入在多大程度上是必需的。在这里，我们描述了消除感觉功能和结构对果蝇胚胎和幼虫蠕动运动模式发育的影响。我们推断，蠕动爬行的神经回路是在完全没有感觉输入的情况下发育的；然而，将这个神经回路整合到实际的运动模式中需要来自感觉系统的额外信息。在没有感觉输入的情况下，运动的极性会紊乱，向后的蠕动波占主导，而向前的蠕动则受到抑制。
