Encoding and control of airflow orientation by a set of Drosophila fan-shaped body neurons

The insect Central Complex (CX) is thought to underlie goal-oriented
navigation but its organization is still not fully understood. We recorded
from genetically-identified CX cell types
in Drosophila and presented directional visual,
olfactory, and airflow cues known to elicit orienting behavior. We found
that a group of neurons targeting the ventral fan-shaped body (ventral
P-FNs) are robustly tuned for airflow direction. Ventral P-FNs did not
generate a “map” of airflow direction. Instead, cells in each hemisphere
were tuned to 45° ipsilateral, forming a pair of orthogonal bases. Imaging
experiments suggest that ventral P-FNs inherit their airflow tuning from
neurons that provide input from the lateral accessory lobe (LAL) to the
noduli (NO). Silencing ventral P-FNs prevented flies from selecting
appropriate corrective turns following changes in airflow direction. Our
results identify a group of central complex neurons that robustly encode
airflow direction and are required for proper orientation to this
stimulus.