Animals adapt their behaviour to environmental stimuli by integrating external sensory inputs with their internal physiological states. In Drosophila melanogaster, factors such as hunger, social isolation, and mating status are known to influence behaviour. These internal states also shape behavioural responses to olfactory cues, suggesting that internal state modulates olfactory processing in the brain.
The mushroom body (MB) is a third-order olfactory processing centre in the Drosophila brain. Kenyon cells (KCs), the intrinsic neurons of the MB, receive olfactory input from antennal lobe projection neurons at a specialized input region called the calyx. There are approximately 2,000 KCs, and the patterns of activity across KCs are thought to encode odour identity. However, how internal states alter odour representations at the level of input region of the mushroom body circuitry remains poorly understood. The calyx is richly innervated by diverse modulatory neurons, including dopaminergic, GABAergic, octopaminergic, serotonergic, and peptidergic (SIFamide-releasing) neurons.
This project aims to investigate:
How neuromodulatory inputs to the calyx contribute to shaping this odour coding.
– Whether internal states (e.g., starvation, social isolation, and mating status) shape odour coding in the MB.
– How neuromodulatory inputs to the calyx contribute to shaping this odour coding.
By examining how internal states and neuromodulators interact to influence sensory processing in the mushroom body, this research seeks to uncover general principles of state-dependent neural coding and behavioural flexibility.
Gokul Madhav
g.madhav(at)devbiol.rwth-aachen.de