Seminars and Colloquia
Biology
Moonwalking flies: Neural basis for directed walking in Drosophila
Tue, Jan 10, 2017,
04:00 PM to 05:00 PM
at Seminar Room 34, 2nd Floor, Main Building
Salil Bidaye
University of California, Berkeley, USA
Most land animals, including fruit flies, have the ability to change their walking direction so as to optimize their behavioral state. This forms a basic component of essential behaviors like courtship, escape and foraging. In a large-scale neural activation screen of fruit flies, we identified a neuronal population which triggered a switch from forward to (persistent) backward walking, dubbed “moonwalking”. Moreover, silencing these “moonwalk” neurons rendered the flies unable to walk backwards in conditions where backward walking was favorable. Identification of this and other GAL4 lines with similar phenotypes, paved the way for pinpointing two causal neuronal types that bring about this phenotype: Moonwalk Descending Neuron (MDN) - command neuron that is necessary and sufficient for initiation of backward walking, and the Moonwalk Ascending Neuron (MAN) – accessory neuron that prolongs the backward walking state by inhibition of a competing forward walking drive. These studies provide a first glimpse into the neural substrate that brings about direction selection in a walking fruit-fly. It also provides a great tool for investigating the upstream brain circuits involved in sensory integration (when to walk backwards, e.g. I’m about to bump into an undesirable object) and downstream nerve cord circuits that execute the direction switch (how to bring about an instantaneous and seamless switch in walking direction).
