Identifying Neuronal Circuits Through Which Vta Mc3r May Affect Feeding And Food Reward
1892 Words8 Pages
Specific aim 2: To identify neuronal circuits through which VTA MC3R may affect feeding and food reward.
The activity of VTA DA neurons has been associated with a variety of behaviors, including reward, salience, aversion, and novelty. VTA neurons differ in their molecular and electrophysiological properties, and differ in their axonal projections and inputs and this has been suggested to be the underlying principle guiding the ability of the VTA to modulate such diverse behaviors (Margolis et al., 2006, Lammel et al., 2008). Intake or presentation of food or food-associated cues activates DA neurons and stimulates DA release in the Acb (Hernandez and Hoebel, 1988, Park and Carr, 1998, Hajnal and Norgren, 2001, Roitman et al., 2004) and is associated with the acquisition of food reward, suggesting that these stimuli activate VTA DA neurons involved in the encoding of reward. Alpha-MSH action in the VTA also increases DA release in Acb and PFC (Torre and Celis, 1986, 1988, Lindblom et al., 2001, Sanchez et al., 2001, Jansone et al., 2004, Yang and Shieh, 2005), yet acts to decrease feeding (Roseberry, 2013, Yen and Roseberry, 2014). This suggests that alpha-MSH results in activation of DA neurons different from those which encode reward. Determining the identity of MC3R-expressing VTA neurons and identifying synaptic circuitries in which these neurons participate is necessary to begin unraveling the mechanisms by which melanocortins act on the mesolimbic dopamine system to