Insect motor control: methodological advances, descending control and inter-leg coordination on the move.

Modern approaches, including high performance video, neurophysiology, and neurogenetics, allow to analyze invertebrate behavior on all levels of generation and performance in an unprecedented way. They allow observation and classification of behavior in controlled conditions, dissection of behavioral sequencing, identification of levels of processing and locations of associated sub-networks and, finally, identification of neuronal components and topologies contributing to specific aspects of behaviors. Recently conceptual and methodological progress has contributed to unraveling the neural structures underlying descending control of insect behavior as well as the mechanisms in charge of generating coordinated locomotor movements of the invertebrate extremities during walking. This brief review summarizes some of the most exciting new findings in these areas of research from the past years.