Protracted cocaine withdrawal produces circadian rhythmic alterations of phosphorylated GSK-3β in reward-related brain areas in rats

Glycogen synthase kinase-3β in the ventral tegmental area mediates diurnal variations in cocaine-induced conditioned place preference in rats

“…These findings were consistent with findings in saline-treated rats that were trained for protracted cocaine withdrawal (Wei et al 2011). Our findings provide important information to enhance our knowledge about the rhythmic expression of GSK-3β activity, an important regulator of circadian rhythm, in the rat brain.…”

“…Bilateral tissue punches of the SCN located approximately from −0.92 mm from bregma (12 gauge), prefrontal cortex (PFC) located approximately 4.2 mm from bregma (16 gauge), VTA located approximately −5.2 mm from bregma (16 gauge) and NAc located approximately 2.2 mm from bregma (16 gauge for two punches) were then taken. Tissue punches were homogenized (10-15 × 3, 5 seconds interval) with an electrical disperser (Wiggenhauser, Sdn Bhd) after 30 minutes in radioimmunoprecipitation assay (RIPA) lysis buffer [Beyotime Biotechnology, Wuhan, China (Wei et al 2011); 20 mM Tris (pH 7.5), 150 mM NaCl, 1% Triton X-100, 2.5 mM sodium pyrophosphate, 1 mM ethylenediaminetetraacetic acid, 1% Na3VO4, 0.5 μg/ml leupeptin and 1 mM phenylmethanesulfonyl fluoride]. Tissue homogenates GSK-3β in diurnal variation of cocaine-induced CPP 997…”

“…The expression of pGSK-3β decreased in the SCN and increased in the NAc and VTA persisted for at least 30 GSK-3β in diurnal variation of cocaine-induced CPP 1003 days, whereas in the PFC decreased during withdrawal for 10 days, but then reversed to abnormally high levels with protracted withdrawal. These results indicate that pGSK-3β may play a role in protracted cocaine withdrawal and contribute to relapse (Wei et al 2011). Our another previous studies (Xu et al , 2011 indicated that the initiation and expression of cocaine-or methamphetamine-induced locomotor sensitization was attenuated by systemic administration of LiCl (100 mg/ kg, i.p.)…”

“…Our previous studies (Wei et al 2011) indicated that blunted circadian rhythms of pGSK-3β persisted for at least 30 days in SCN, PFC, NAc and VTA, with the exception of 10 days in the SCN and nucleus accumbens (NAc). The expression of pGSK-3β decreased in the SCN and increased in the NAc and VTA persisted for at least 30 GSK-3β in diurnal variation of cocaine-induced CPP 1003 days, whereas in the PFC decreased during withdrawal for 10 days, but then reversed to abnormally high levels with protracted withdrawal.…”

Short photoperiod condition increases susceptibility to stress in adolescent male rats

“…A total of six blood samples were collected. Collections occurred every 4 h (8:00 PM, 12:00 AM, 4:00 AM, 8:00 AM, 12:00 PM, and 4:00 PM) according to our previous studies [18,21,22]. Immediately after each blood sample was drawn, a 1 ml sample was kept in a tube with the anticoagulant ethylenediaminetetraacetic acid.…”