Dominance status is associated with a variation in cannabinoid receptor 1 expression and amphetamine reward

• Published in: Pharmacology, biochemistry and behavior Vol. 221; p. 173483
• Main Authors: Migliaro, Martin, Sánchez-Zavaleta, Rodolfo, Soto-Tinoco, Eva, Ruiz-Contreras, Alejandra E., Méndez-Díaz, Mónica, Herrera-Solís, Andrea, Pérez de la Mora, Miguel, Prospéro-García, Oscar E.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.11.2022
• Subjects: Amphetamine - pharmacology; Animals; CB1R; Central Nervous System Stimulants - metabolism; Central Nervous System Stimulants - pharmacology; Dominance status; Drug reward; Endocannabinoid system; Male; Nucleus Accumbens - metabolism; Psychostimulant; Rats; Receptor, Cannabinoid, CB1 - genetics; Reward; Social brain; CB2R; Dominance status; Sub; eCBS; Social brain; PRE; Dom; DAGLa; EPM; Drug reward; AG; DP; NAc; mPFC; Endocannabinoid system; LIRL; TEST; FAAH1; HIWL; AMPH; Psychostimulant; MDS; A-CPP; CB1R
• ISSN: 0091-3057; 1873-5177
• DOI: 10.1016/j.pbb.2022.173483

The rewarding effects of psychostimulants appear to be distinct between dominant and subordinate individuals. In turn, the endocannabinoid system is an important modulator of drug reward in the nucleus accumbens and medial prefrontal cortex, however the connection with social dominance is yet to be established. Male rats were classified as dominant or subordinate on the basis of their spontaneous agonistic interactions and drug reward was assessed by means of conditioned place preference with amphetamine (AMPH). In addition, the expression of CB1R, CB2R, FAAH1, and DAGLa was quantified from accumbal and cortical tissue samples. Our findings demonstrate that dominant rats required a lesser dose of AMPH to acquire a preference for the drug-associated compartment, thereby suggesting a higher sensitivity to the rewarding effects of AMPH. Furthermore, dominants exhibited a lower expression of CB1R in the medial prefrontal cortex and nucleus accumbens. This study illustrates how CBR1 expression could differentiate the behavioral phenotypes associated to social dominance. •Dominant rats are more sensitive to the rewarding effects of d-amphetamine.•Higher sensitivity of dominants to the rewarding effects of d-amphetamine cannot be attributed to anxiety.•Dominant rats have a lower endogenous expression of CB1R in the mPFC and the NAc.