Controlling the Motor Neuron

Abstract

Publisher Summary This chapter describes three sensory-to-motor reflexes and their associated central circuits and synapses. The uniquely identifiable neurons comprising these reflex circuits offer an excellent opportunity for investigating detailed molecular mechanisms underlying the development and operation of the central nervous system (CNS). Some of the genetic approaches used to characterize these reflex circuits are used to investigate the substrate underlying other behaviors in Drosophila. In particular the GAL4/UAS system has become the “technique of choice” for identifying neural substrates participating in such behaviors as olfactory jump, olfactory learning, and sexual behavior. The reflex neural circuits characterized are composed of relatively few neurons that are uniquely identified for example the hair plate reflex circuit employs only eight sensory neurons that exhibit synaptic connections with a single identified motorneuron. Because of the simplicity of the three reflex circuits, the chapter analyzes the function of gene products in establishing both dendritic and axonal anatomy in conjunction with their function in shaping the physiology of central neurons and synapses.