S-093
Consummatory behaviors induced by growth hormone secretagogue receptor (GHSR) activation depends partially on dopamine neurons activity
Taiel Podesta4, Franco Barrile1,2,3, Mario Perelló1,2,3
  1. Laboratory of Neurophysiology of the Multidisciplinary Institute of Cell Biology [IMBICE]
  2. Argentine Research Council (CONICET)
  3. Scientific Research Commission, Province of Buenos Aires (CIC-PBA)
  4. National University of La Plata
Presenting Author:
Taiel Podesta
taielpodesta@gmail.com
The consumption of energy-dense foods is partially mediated by the activity of midbrain dopamine neurons. This activity is modulated by diverse signals, including gastrointestinal hormones such as ghrelin, a stomach-derived peptide that acts through the growth hormone secretagogue receptor (GHSR). GHSR is highly expressed in various brain regions, including midbrain dopamine neurons, and its activation induces several physiological changes, such as increased food intake and growth hormone release. Here, we aimed to gain insight into the role of dopamine neurons in mediating GHSR-regulated actions. First, we used an inhibitory designer receptor exclusively activated by designer drugs (DREADD) to evaluate the role of dopamine neurons in modulating eating behaviors. We found that inhibition of dopamine neurons reduced the consumption of the non-caloric sweetener saccharin in mice under 40% caloric restriction but did not alter high-fat diet intake in the same mice subjected to a 4-day binge-eating protocol. Next, we tested whether dopamine neuron inhibition affects ghrelin-induced actions. We found that inhibition of dopamine neurons reduced ghrelin-induced locomotor activity but had no effect on ghrelin-induced food intake. These results suggest that activation of dopamine neurons is required for some, but not all, GHSR-mediated consummatory actions.