Speed dependent descending control of innate freezing behavior inDrosophila melanogaster [article]

Ricardo Zacarias, Shigehiro Namiki, Gwyneth Card, Maria L Vasconcelos, Marta A Moita
2017 bioRxiv   pre-print
The most fundamental choice an animal has to make when it detects a predator, or other threats, is whether to freeze, reducing its chances of being noticed, or to flee to safety. Here we show thatDrosophila melanogasterexposed to looming stimuli in a confined arena either froze or fled. The probability of freezing versus fleeing was modulated by the fly's walking speed at the time of threat, demonstrating that freeze/flee decisions were context dependent. We describe a pair of descending
more » ... f descending neurons crucially implicated in freezing. Genetic silencing of P9 descending neurons disrupted freezing yet did not prevent fleeing. Optogenetic activation of both P9 neurons induced running and freezing in a state-dependent manner. Our findings establish walking speed as a key factor in defensive response choices and reveal a pair of descending neurons as a critical component in the circuitry mediating selection and execution of freezing or fleeing behaviors.
doi:10.1101/234443 fatcat:b7qey76n3zemljb4fiyikfy7x4