Effects of chronic cocaine exposure on the circadian rhythmic expression of the clock genes in reward-related brain areas in rats.

Effects of chronic cocaine exposure on the circadian rhythmic expression of the clock genes in reward-related brain areas in rats. Behav Brain Res. 2019 Jan 22;: Authors: Wang DQ, Wang XL, Wang CY, Wang Y, Li SX, Liu KZ Abstract Drug addiction is a widespread social problem, which not only brings adverse consequences to the human body, but also causes great burden to the society. However, it's still unclear how the long-term and sustained cocaine exposure will affect clock genes' expression in the reward related brain areas. We hypothesize that chronic cocaine exposure causes changes in the circadian rhythmic expression of clock genes in brain regions associated with reward, since previous studies have shown that cocaine use causes circadian disorders. Sprague-Dawley male rats were administrated with cocaine 20 mg/kg at ZT4 through intraperitoneal injection for 21 consecutive days. Twenty-four hours after the last cocaine administration brain samples were collected at 4-hour intervals for 24 hours (every 4h: ZT 0; ZT 4; ZT 8; ZT 12; ZT 16; ZT 20) to examine expression of rPer1, rPer2, rPer3, rCry, rBmal1 and rClock by quantitative real-time reverse-transcription polymerase chain reaction (RT-PCR). We found that chronic cocaine exposure to rats resulted in significantly disturbances in expression of clock genes in reward related brain areas compared to saline - treated rats. In cocaine-treated rats,rPer1 expression in the suprachi...
Source: Behavioural Brain Research - Category: Neurology Authors: Tags: Behav Brain Res Source Type: research