The brain represents the master coordinator of appetite and energy expenditure, employing interwoven neurological circuits to continually appraise and respond to changes in energy state.
Our research aims to discover and characterise these brain circuits using cutting edge technology with the objective of locating points within the pathway that are amenable to manipulation with manmade (drug) or natural (hormone) substances.
We also examine the impact of diet and body weight on circuit rewiring and mechanisms restore appropriate system connectivity and activity.
The ultimate aim of our research is to identify new treatments for obesity and type 2 diabetes.
We aim to elucidate the neuroendocrinology of energy homeostasis and neural influences on peripheral metabolism, in order to define novel therapeutic targets for obesity and type 2 diabetes.
There is significant genetic and pharmacological evidence that central melanocortin pathways, mostly through melanocortin-4 receptors, are critical in the regulation of neuroendocrine and behavioural parameters associated with energy balance/type 2 diabetes.
However, relatively little is known about the downstream pathways involved. We are adopting complementary neuroanatomical, pharmacological, genetic, physiological, and behavioural approaches to investigate such brain circuitry.
Specifically, our data suggest that the central serotonin system modulates melanocortin pathways, and we are currently exploring the expression of different serotonin receptors on melanocortin-containing cell bodies, and their differential modulation of effects on key nuclei in the hypothalamus and brainstem.
Garfield AS, Shah BP, Madara JC, Burke LK, Patterson CM, Flak J, Neve RL, Evans ML, Lowell BB, Myers MG Jr, Heisler LK. A parabrachial-hypothalamic cholecystokinin neurocircuit controls counterregulatory responses to hypoglycemia. Cell Metabolism, 2014; 20(6):1030-7.
Flak JN, Patterson CM, Garfield AS, D'Agostino G, Goforth PB, Sutton AK, Malec PA, Wong JM, Germani M, Jones JC, Rajala M, Satin L, Rhodes CJ, Olson DP, Kennedy RT, Heisler LK, Myers MG Jr. Leptin-inhibited PBN neurons enhance responses to hypoglycemia in negative energy balance. Nature Neuroscience, 2014; 17(12):1744-50.
Burke LK, Doslikova B, D'Agostino G, Garfield AS, Farooq G, Burdakov D, Low MJ, Rubinstein M, Evans ML, Billups B, Heisler LK. 5-HT obesity medication efficacy via POMC activation is maintained during aging. Endocrinology, 2014; 155(10):3732-8.
Cowley M, Garfield AS, Madon-Simon M, Charalambous M, Clarkson RW, Smalley MJ, Kendrick H, Isles AR, Parry AJ, Carney S, Oakey RJ, Heisler LK, Moorwood K, Wolf JB, Ward A. Developmental programming mediated by complementary roles of imprinted Grb10 in mother and pup. PLoS Biology, 2014; 12(2):e1001799.
Stanley S, Domingos AI, Kelly L, Garfield A, Damanpour S, Heisler L, Friedman J. Profiling of Glucose-Sensing Neurons Reveals that GHRH Neurons Are Activated by Hypoglycemia. Cell Metabolism 2013; 18(4):596-607.