Alex Thomas, Bartness Lab

The role of GHSRs in Appetitive and Consummatory Feeding Behavior.

The stomach-derived “hunger hormone” ghrelin increases in circulation in direct response to time since the last meal.  We previously demonstrated peripheral injection of ghrelin potently stimulates food foraging (FF) food hoarding (FH) and food intake (FI) in Siberian hamsters.  It remains, however, unknown if central ghrelin is necessary and sufficient to increase these behaviors regardless of peripheral manipulation.  Here, we injected three doses (0.01 µg, 0.1 µg, and 1.0 µg) of ghrelin into the third ventricle (3V) of Siberian hamsters and measured FF, FH, and FI.  To test the effects of 3V ghrelin receptor blockade, we used GHSR1a antagonist JMV2959 to block these behaviors in response to food deprivation or a peripheral ghrelin challenge.  Finally, we examined neuronal activation in the arcuate nucleus (Arc) and paraventricular hypothalamic nucleus (PVH) in response to peripheral ghrelin administration and 3V GHSR1a antagonism.  Ghrelin 3V stimulated food intake at 2-4 h and food hoarding through day 4.  JMV2959 3V pretreatment successfully blocked peripheral ghrelin-induced increases in FF, FH and FI and FH at all time points examined and food deprivation-induced increases in FF, FH and FI up to four hours.  c-Fos-immunoreactivity (-ir) was significantly reduced in the PVH but not the Arc following pretreatment with JMV2959.  Collectively, these data suggest central GHSR1a activation is both necessary and sufficient to increase appetitive and consummatory behaviors in Siberian hamsters.

This talk was delivered at Georgia State University’s Neuroscience Institute Breakfast Lecture Series (NIBL) on 6.4.15. Learn more about NIBL talks here:  http://neuroscience.gsu.edu/connections/nibl/ 

An event sponsored by Neuroscience Graduate Student Association (NGSA)