Discordant Effects of Cannabinoid 2 Receptor Antagonism/Inverse Agonism During Adolescence on Pavlovian and Instrumental Reward Learning in Adult Male Rats

• DOI: 10.3389/fnsyn.2021.732402
• Publication Date: 2021-09-03T18:02:48Z
• Authors: Danna Ellner; Bryana Hallam; Jude A. Frie; Hayley H. A. Thorpe; Muhammad Shoaib; Hakan Kayir; Bryan W. Jenkins; Jibran Y. Khokhar
• Keywords: Inverse agonist; Afterhyperpolarization

The endocannabinoid system is responsible for regulating a spectrum of physiological activities and plays critical role in the developing brain. During adolescence, particularly sensitive to external insults that may change brain’s developmental trajectory. Cannabinoid receptor type 2 (CB2R) was initially thought predominantly function peripheral nervous system, but more recent studies have implicated its mesolimbic pathway, network largely attributed reward circuitry motivated behavior, which undergoes extensive changes during adolescence. It therefore important understand how CB2R modulation adolescence can impact reward-related behaviors adulthood. In this study, adolescent male rats (postnatal days 28–41) were exposed low or high dose antagonist/inverse agonist SR144528 Pavlovian autoshaping instrumental conditional behavioral outcomes measured SR144528-treated had significantly slower acquisition task, seen by less lever pressing behavior over time [ F (2, 19) = 5.964, p 0.010]. Conversely, there no effect exposure on conditioning. These results suggest differentially impacts reward-learning