Neural network function requires an appropriate balance of excitation and inhibition to be maintained by homeostatic plasticity.
However, little is known about homeostatic mechanisms in the intact central brain in vivo. Here, we study homeostatic plasticity in the Drosophila mushroom body, where Kenyon cells receive feedforward excitation from olfactory projection neurons and feedback inhibition from the anterior paired lateral neuron (APL).
We show that prolonged (4 d) artificial activation of the inhibitory APL causes increased Kenyon cell odor responses after the artificial inhibition is removed, suggesting that the mushroom body compensates for excess inhibition.
In contrast, there is little compensation for lack of inhibition (blockade of APL). The compensation occurs through a combination of increased excitation of Kenyon cells and decreased activation of APL, with differing relative contributions for different Kenyon cell subtypes.
Our findings establish the fly mushroom body as a model for homeostatic plasticity in vivo.
Andrew Lin studied biology at Harvard and did his PhD with Christine Holt at the University of Cambridge.
He was a Sir Henry Wellcome Postdoctoral Fellow with Gero Miesenböck at the University of Oxford. He is now a Lecturer at the University of Sheffield, where he started his lab in 2015, funded by a Starting Grant from the European Research Council.