Morphological characterization of the entire interneuron population reveals principles of neuromere organization in the Ventral nerve cord of Drosophila

Abstract

Decisive contributions to our understanding of the mechanisms underlying the development of the nervous system have been made bystudies performed at the level of single, identified cells in the fruit fly Drosophila. While all the motor neurons and glial cells in thoracicand abdominal segments of the Drosophila embryo have been individually identified, few of the interneurons, which comprise the vastmajority of cells in the CNS, have been characterized at this level. We have applied a single cell labeling technique to carry out a detailedmorphological characterization of the entire population of interneurons in abdominal segments A1-A7. Based on the definition of a setof spatial parameters specifying axonal projection patterns and cell body positions, we have identified 270 individual cell types as thecomplete hemisegmental set of interneurons and placed these in an interactive database. As well as facilitating analyses of developmentalprocesses, this comprehensive set of data sheds light on the principles underlying the formation and organization of an entire segmentalunit of the CNS. © 2011 the authors.