Topic: olfactory learning

Animals flexibly adjust behavior depending on the environmental context and learned experience. The nematode C. elegans modulates its preference towards an odor source depending on its pairing with food or starvation. However, precisely how the worm alters its navigation strategy in response to olfactory learning has not been characterized, in part due to challenges with measuring the exact odor cues in the environment. Here, we used a novel apparatus and optogenetics to measure and then model learned odor-navigation strategies in worms. Specifically, we modelled navigation using a Mixture of

Presynaptic forms of plasticity occur throughout the nervous system and play an important role in learning and memory but the underlying molecular mechanisms are insufficiently understood. Here we show that the small GTPase Rab3 is a key mediator of cyclic AMP (cAMP)-induced presynaptic plasticity in Drosophila. Pharmacological and optogenetic cAMP production triggered concentration-dependent alterations of synaptic transmission, including potentiation and depression of evoked neurotransmitter release, as well as strongly facilitated spontaneous release. These changes correlated with a nanosco