dendritic targeting in the leg neuropil of drosophila the role of midline signalling molecules in generating a myotopic map树突针对腿部神经纤维网的果蝇中线信号分子的作用生成myotopic地图.pdfVIP

Dendritic Targeting in the Leg Neuropil of Drosophila: The Role of Midline Signalling Molecules in Generating a Myotopic Map 1 1 2 2 1 David J. Brierley , Eric Blanc , O. Venkateswara Reddy , K. VijayRaghavan , Darren W. Williams * 1 Medical Research Council (MRC) Centre for Developmental Neurobiology, King’s College London, London, United Kingdom, 2 National Centre for Biological Sciences, Tata Institute of Fundamental Research, Bangalore, India Abstract Neural maps are emergent, highly ordered structures that are essential for organizing and presenting synaptic information. Within the embryonic nervous system of Drosophila motoneuron dendrites are organized topographically as a myotopic map that reflects their pattern of innervation in the muscle field. Here we reveal that this fundamental organizational principle exists in adult Drosophila, where the dendrites of leg motoneurons also generate a myotopic map. A single postembryonic neuroblast sequentially generates different leg motoneuron subtypes, starting with those innervating proximal targets and medial neuropil regions and producing progeny that innervate distal muscle targets and lateral neuropil later in the lineage. Thus the cellular distinctions in peripheral targets and central dendritic domains, which make up the myotopic map, are linked to the birth-order of these motoneurons. Our developmental analysis of dendrite growth reveals that this myotopic map is generated by targeting. We demonstrate that the medio-lateral positioning of motoneuron dendrites in the leg neuropil is controlled by the midline signalling systems Slit-Robo and Netrin-Fra. These