The discovery that gut microbiota can influence behavior is emerging as an exciting new concept in
neurophysiology and disease. In humans, links have been drawn between the gut microbiome and
neurological disorders such as depression, migraine, anxiety, autism, schizophrenia, and neurodegenerative
disorders. However, the question of causality in microbiome studies remains unanswered and the molecular
basis of the complex interaction of diet, microbiota, and the brain is still poorly understood. The goal of this
proposal is to identify microbiome factors that contribute to neural function and to uncover an important
mechanistic link between diet, gut microbiota, and neurological disorders. The nematode C. elegans is ideally
suited for this approach because both its neural circuits and bacterial diets are simple, well-defined and
genetically tractable. We have generated and characterized a C. elegans model for a channelopathy that
provides a sensitized genetic background to study gut-brain interactions. Specifically, we have isolated a novel
gain-of-function (gf) mutation in the neuronal voltage-gated calcium channel gene unc-2/CaV2a. Similar
mutations in human ortholog, CACNA1A, cause Familial Hemiplegic Migraine-type I (FHM1) in humans. C.
elegans unc-2/CaV2a(FHM1) mutants have increased synaptic transmission and display clonic seizures. We
made the striking observation that a diet of bacteria that make vitamin B12 greatly reduces the seizure
behavior of unc-2/CaV2a(FHM1) mutants. Vitamin B12 is an essential nutrient for brain health. Vitamin B12
deficiency has been associated with many neurological disorders, including depression, schizophrenia,
Alzheimer's and migraine. However, how vitamin B12 impacts neural function is largely unclear. We will
determine how vitamin B12 changes metabolic processes in the gut, and how such changes impair neural
function in the brain. In addition, we will take advantage of our unique C. elegans migraine model to identify
beneficial microbiota and other factors that improve neural health. These experiments will provide valuable
understanding into elusive mechanisms of gut-brain communication and can ultimately inform the use of
probiotics to improve symptoms of neurological disorders.