Song-associated reward correlates with endocannabinoid-related gene expression in male European starlings (Sturnus vulgaris).
Vocal communication is required for successful social interactions in numerous species. During the breeding season, songbirds produce songs that are reinforced by behavioral consequences (e.g., copulation). However, some songbirds also produce songs not obviously directed at other individuals. The consequences maintaining or reinforcing these songs are less obvious and the neural mechanisms associated with undirected communication are not well-understood. Previous studies indicate that undirected singing is intrinsically rewarding and mediated by opioid or dopaminergic systems; however, endocannabinoids are also involved in regulating reward and singing behavior. We used a conditioned place preference paradigm to examine song-associated reward in European starlings and quantitative real-time PCR to measure expression of endocannabinoid-related neural markers (CB1, FABP7, FABP5, FAAH, DAGLα), in brain regions involved in social behavior, reward and motivation (ventral tegmental area [VTA], periaqueductal gray [PAG], and medial preoptic nucleus [POM]), and a song control region (Area X). Our results indicate that starlings producing high rates of song developed a conditioned place preference, suggesting that undirected song is associated with a positive affective state. We found a significant positive relationship between song-associated reward and CB1receptors in VTA and a significant negative relationship between song-associated reward and CB1in PAG. There was a significant positive relationship between reward and the cannabinoid transporter FABP7 in POM and a significant negative relationship between reward and FABP7 in PAG. In Area X, FABP5 and DAGLα correlated positively with singing. These results suggest a role for endocannabinoid signaling in vocal production and reward associated with undirected communication.
Department of Zoology, 426 Birge Hall, 430 Lincoln Drive, University of Wisconsin-Madison, Madison, WI 53706, USA. Electronic address: ahahn4@wisc.edu.
Allison H
AH
Hahn
Department of Zoology, 426 Birge Hall, 430 Lincoln Drive, University of Wisconsin-Madison, Madison, WI 53706, USA.
Devin P
DP
Merullo
Department of Zoology, 426 Birge Hall, 430 Lincoln Drive, University of Wisconsin-Madison, Madison, WI 53706, USA.
Jeremy A
JA
Spool
Department of Zoology, 426 Birge Hall, 430 Lincoln Drive, University of Wisconsin-Madison, Madison, WI 53706, USA.
Caroline S
CS
Angyal
Department of Zoology, 426 Birge Hall, 430 Lincoln Drive, University of Wisconsin-Madison, Madison, WI 53706, USA.
Sharon A
SA
Stevenson
Department of Zoology, 426 Birge Hall, 430 Lincoln Drive, University of Wisconsin-Madison, Madison, WI 53706, USA.
Lauren V
LV
Riters
D000581:Amidohydrolases / Q000378:metabolism; D000818:Animals; D030161:Avian Proteins / Q000378:metabolism*; D003214:Conditioning, Classical / Q000502:physiology; D063388:Endocannabinoids / Q000378:metabolism*; D050556:Fatty Acid-Binding Proteins / Q000378:metabolism; D015870:Gene Expression; D008071:Lipoprotein Lipase / Q000378:metabolism; D008297:Male; D010487:Periaqueductal Gray / Q000378:metabolism*; D011301:Preoptic Area / Q000378:metabolism*; D043884:Receptor, Cannabinoid, CB1 / Q000378:metabolism; D012201:Reward; D046749:Starlings / Q000378:metabolism*; D014828:Vocalization, Animal; D000099252:Fatty Acid Amide Hydrolases
D000581:Amidohydrolases; D030161:Avian Proteins; D063388:Endocannabinoids; D050556:Fatty Acid-Binding Proteins; D008071:Lipoprotein Lipase; D043884:Receptor, Cannabinoid, CB1; D000099252:Fatty Acid Amide Hydrolases
conditioned place preference; endocannabinoid; reward; songbird; vocal communication