Development of larval motor circuits in Drosophila

Abstract

How are functional neural circuits formed during development? Despite recent advances in our understanding of the development of individual neurons, little is known about how complex circuits are assembled to generate specific behaviors. Here, we describe the ways in which Drosophila motor circuits serve as an excellent model system to tackle this problem. We first summarize what has been learned during the past decades on the connectivity and development of component neurons, in particular motor neurons and sensory feedback neurons. We then review recent progress in our understanding of the development of the circuits as well as studies that apply optogenetics and other innovative techniques to dissect the circuit diagram. New approaches using Drosophila as a model system are now making it possible to search for developmental rules that regulate the construction of neural circuits.

Developmental Characterization of Tail Movements in the Appendicularian Urochordate <b><i>Oikopleura dioica</i></b>

“…These changes are effectuated over the course of a few hours. Thus, these two behaviors exhibit a period of maturation, as do a number of similar behaviors in other species [Saint-Amant and Drapeau, 1998;Marder and Rehm, 2005;Kohsaka et al, 2012]. The extent to which this reflects central neural versus peripheral muscular development is unclear, but it potentially reflects both, as the behaviors appear shortly after hatching, which is only 4 h after gastrulation.…”

Dendritic growth gated by a steroid hormone receptor underlies increases in activity in the developing Drosophila locomotor system

“…Its well-characterized neuromuscular system offers unprecedented access to ask how the nervous system changes during periods of rapid animal growth (9). In Drosophila, as in vertebrates, muscles and neuromuscular junctions enlarge with increases in animal body size (8,(10)(11)(12).…”

Gap Junction–Mediated Signaling from Motor Neurons Regulates Motor Generation in the Central Circuits of LarvalDrosophila

“…Larval Drosophila is emerging as an excellent model system for studying motor pattern generation since one can apply powerful genetic tools including a large collection of Gal4-drivers Li et al, 2014) to study the function of individual component neurons in a numerically simple nervous system (Heckscher et al, 2012(Heckscher et al, , 2015Kohsaka et al, 2012Kohsaka et al, , 2014Vogelstein et al, 2014;Couton et al, 2015). Furthermore, previous development of a platform for electronic microscope (EM) image data reconstruction of the entire nervous system of the larval CNS now allows mapping of the circuit structure that mediates specific behaviors (Heckscher et al, 2015;Ohyama et al, 2015;Fushiki et al, 2016;Schneider-Mizell et al, 2016).…”