Characterizing excitatory transmission in melanin-concentrating hormone neurons

Bowes, Sherri C. (2020) Characterizing excitatory transmission in melanin-concentrating hormone neurons. Masters thesis, Memorial University of Newfoundland.

[English] PDF - Accepted Version Available under License - The author retains copyright ownership and moral rights in this thesis. Neither the thesis nor substantial extracts from it may be printed or otherwise reproduced without the author's permission. Download (1MB)

Abstract

Melanin-concentrating hormone (MCH) neurons of the lateral hypothalamus are involved in homeostatic mechanisms including energy balance and sleep wake cycles. Glutamate is an excitatory transmitter that is released by neurons and astrocytes, providing an excitatory control over neuronal activity. Here, I investigated the role of glutamate transporters and glutamate receptors in excitatory signaling onto MCH neurons. Using patch clamp electrophysiology, I have identified three distinct excitatory glutamatergic currents in MCH neurons: fast EPSC, slow EPSC, and tonic currents. I demonstrate that presynaptic train stimulation induces EPSCs with two distinct time courses (fast and slow) while tonic currents are due to ambient glutamate that accumulates when glutamate transporters are inhibited. Furthermore, these currents are mediated by distinct glutamate receptor pools, which are under the regulation of different glutamate transporters. This work contributes to the ongoing understanding of basic excitatory signaling in MCH neurons. Given the known role of MCH in promoting sleep and weight gain this may have functional implications for sleep and energy homeostasis.

Actions (login required)

View Item