The neural basis of goal directed behavior in insects

To purposefully orient in space, an animal has to compare its body orientation with its current goal and initiate a turn if the two angles do not match.

In insects, this fundamental process is accessible at the level of identified neurons, all compressed into a single brain area called the central complex (CX). While heading encoding is well understood, goal encoding remains elusive. Yet, recent data point towards a key role of one CX subregion, the noduli.

We will thus examine if and how goal directed movements emerge from the neural circuits of the CX noduli.

First, we will compare ancient, wingless insects, which lack noduli, to bees - modern insects with highly complex noduli.

Second, we will exploit our finding that noduli gradually develop in termites when transitioning from nymphs into the reproductive cast.

We will use connectomics to extract the involved neural circuits, computational circuit modeling to predict behavioral correlates, and test those predictions with behavioral experiments.

We will reveal if noduli are indeed required for goal directed behavior, and will aim at establishing the developmental switch from a seemingly ancient to a modern CX between termite casts as a model for the key evolutionary jump from wingless to winged insects.

Overall, the anticipated results will move us closer to answering two major open questions in biology: Why do animals do what they do? And second, can we pinpoint the evolutionary origin of purposeful animal behavior?