The role of metabotropic glutamate receptors in the modulation of behaviour across different sensory contexts in C. elegans Event

Glutamate is the main excitatory neurotransmitter of the mammalian CNS. Glutamatergic neurotransmission occurs through two classes of receptor, ionotropic receptors (iGluRs) and metabotropic receptors (mGluRs). The metabotropic glutamate receptors (mGluRs) perform an important neuromodulatory role at the synapse and contribute to mechanisms underlying synaptic plasticity and complex behaviours. mGluR dysfunction has been identified in a number of different neuropsychiatric conditions, including schizophrenia, anxiety disorders and Fragile X syndrome (FXS). Individuals with Fragile X will often display learning and memory deficits together with autistic phenotypes, including an impaired ability to process contextual environmental cues and then co-ordinate suitable behavioural responses.

The C. elegans nervous system is much simpler than our own, yet many of the fundamental features are conserved. Combined with a defined connectome, simple behaviours and amenability to transgenic techniques C. elegans provides a platform to further understand receptor function at the molecular, cellular and systems level. The C. elegans genome predicts three mGluR homologues, mgl-1, mgl-2 and mgl-3. Here we have utilised C. elegans as a model system to further understand mGluR function. Behavioural and electrophysiological analysis has identified that MGL subtypes are required for the activity of neural circuits that underlie the co-ordination of context-dependent behaviour in response to sensory cues. This understanding could provide further insight into CNS disorders such as FXS where glutamatergic neurotransmission is disrupted culminating in impaired processing across different sensory contexts.