5-HT1A receptor agonism in the basolateral amygdala increases mutual-reward choices in rats

Abstract

Rats show mutual-reward preferences, i.e., they prefer options that result in a reward for both themselves and a conspecific partner to options that result in a reward for themselves, but not for the partner. In a previous study, we have shown that lesions of the basolateral amygdala (BLA) reduced choices for mutual rewards. Here, we aimed to explore the role of 5-HT1A receptors within the BLA in mutual-reward choices. Rats received daily injections of either 50 or 25 ng of the 5-HT1A receptor agonist 8-OH-DPAT or a vehicle solution into the BLA and mutual-reward choices were measured in a rodent prosocial choice task. Compared to vehicle injections, 8-OH-DPAT significantly increased mutual-reward choices when a conspecific was present. By contrast, mutual-reward choices were significantly reduced by 8-OH-DPAT injections in the presence of a toy rat. The effect of 8-OH-DPAT injections was statistically significant during the expression, but not during learning of mutual-reward behavior, although an influence of 8-OH-DPAT injections on learning could not be excluded. There were no differences between 8-OH-DPAT-treated and vehicle-treated rats in general reward learning, behavioral flexibility, locomotion or anxiety. In this study, we have shown that repeated injections of the 5-HT1A receptor agonist 8-OH-DPAT have the potential to increase mutual-reward choices in a social setting without affecting other behavioral parameters.

Brain Site-Specific Inhibitory Effects of the GLP-1 Analogue Exendin-4 on Alcohol Intake and Operant Responding for Palatable Food

“…Because of its relevance during reward-seeking behavior, we decided to examine the effects of direct injection into the BLA. The BLA, which projects to the NAcC, is critical for reward-seeking behavior [ 56 , 57 ]. Furthermore, long-term ethanol consumption alters several mRNAs in the BLA of rats [ 58 ], and previous research suggests that the BLA is necessary for stress-induced drug-seeking and drug-taking behavior [ 59 ].…”