Fruit flies keep a direction in mind with a split neural circuit
A peer-reviewed Nature study examined how fruit flies keep moving toward an odour-associated goal after the smell disappears. New York University researchers combined behaviour, neural imaging and cellular recordings with simulations. Two interconnected cell groups separate tracking the current heading from retaining a goal, offering an experimental account of short-lived directional memory in flies.
Science··Morning
Flies retain the direction of a vanished smell
Fruit flies can continue walking toward an odour-associated goal after the smell disappears. Katherine Nagel’s team at New York University examined this behaviour in a peer-reviewed Nature experiment. Each fly walked on a ball supported by air as researchers changed the wind and apple-cider-vinegar odour. Continuing in the previous goal direction was the behavioural measure of short-lived directional memory. The accompanying brain activity was followed through neural imaging and electrical measurements inside cells.[1]
Two cell groups separate heading from the goal
The brain’s fan-shaped body contains interconnected PFG and hΔK cell groups. Computational models combine fast inhibitory interactions with slower excitation to maintain directional activity. When hΔK cells are inhibited, PFG activity can follow the fly’s current heading. Odour-associated release from inhibition allows that heading to become a persistent goal signal. This arrangement combines rapid writing of a new direction with temporary maintenance of an earlier one.[1]
A switching cell group remains under investigation
An inhibitory group called FB5V is associated with the switch between these states. The authors identify targeted activation and silencing experiments as necessary to test its causal role more directly. Other connections may contribute to slowly persistent activity. The findings concern a fly’s navigation circuit, combining animal experiments with simulations; the corresponding arrangement in human working memory remains outside the experiment’s scope.[1]
