THE ROLE OF TRIGEMINAL ISL1 NEURONS IN FEEDING BEHAVIOUR

Abstract

Current research into feeding regulation is dominated by a top-down approach in establishing hypothalamic driven circuits of appetite. However, the link between hypothalamic feeding regions and the motor control of consummatory behaviour remains unclear. The work in this thesis identified a marker, ISL1, for brain regions that control masticatory muscles (ISL1MesV and ISL1MoV). Analysis of the inputs to ISL1MoV revealed subcortical regulation of masticatory muscles. Chronic silencing of ISL1MoV resulted in mice exhibiting a starvation phenotype due to impaired masticatory function. Functional manipulations of the activity of ISL1MoV and MoV projecting limbic neurons in feeding assays revealed changes to the feeding patterns of mice. Additionally, the effects of neural transmission of inhibitory limbic neurons on ISL1MoV neurons revealed that these neurons depolarize in response to GABA. This thesis represents a pioneering study of a cell type specific investigation of the anatomical and functional characterization of trigeminal ISL1 neurons.