Mandi Luellen, Melody S. Kirby, and Cynthia T. Hsu

Metabotropic glutamate receptors (mGluRs) are G-protein-coupled receptors that regulate neurotransmission, synaptic plasticity, and neuronal excitation. Disruptions to mGluR function have been implicated in psychiatric disorders including schizophrenia and mood disorders. Here, we present preliminary data characterizing knockdown of two metabotropic glutamate receptor homologs in Drosophila, mangetout (mtt) and metabotropic glutamate receptor (mGluR), in sleep, locomotor, and feeding assays. We find that constitutive pan-neuronal knockdown of mangetout is lethal while adult-specific knockdown leads to drastic impairments in locomotion. In contrast, while previous studies have reported sleep deficits in constitutive pan-neuronal knockdown of mGluR, we find that adult-specific knockdown does not compromise sleep or locomotion. This suggests that the role of mGluR in sleep is developmental, in contrast to mtt, which has significant effects in adult behavior. Supplementing mtt knockdown flies with octopamine and serotonin precursors does not rescue locomotor phenotypes. Our findings may indicate an overlooked role of mtt as a homolog for metabotropic glutamate receptors and a potential target for pharmacological screens.

California State University, Fresno