“…The Htr2c gene encodes the serotonin (5-HT) G-protein coupled receptor (GPCR) 5-HT 2C receptor (5-HT 2C R) and our transcriptomic analyses identified lower Htr2c mRNA expression in the mPFC of abstinent HC vs. LC rats (FC: 1.510), aligning with lower 5-HT 2C R protein expression previously observed in the mPFC during abstinence ( Anastasio et al, 2014b ; Swinford-Jackson et al, 2016 ). An investigational 5-HT 2C R agonist evinced efficacy, but reduced potency, to inhibit cocaine-seeking during abstinence ( Swinford-Jackson et al, 2016 ), supporting the concept that 5-HT 2C R agonists ( Fletcher et al, 2004 ; Cunningham et al, 2011 ; Harvey-Lewis et al, 2016 ; Anastasio et al, 2020 ), may ameliorate hypofunctional 5-HT 2C R neurotransmission as a core mediator of relapse vulnerability (for reviews) ( Howell and Cunningham, 2015 ; Cunningham et al, 2020 ). However, while the 5-HT 2C R agonist lorcaserin reduced craving in non-treatment seeking CUD participants ( Pirtle et al, 2019 ; Johns et al, 2021 ), this medication may facilitate continued abstinence in treatment-seeking CUD participants (NCT03007394).…”