Circadian variation in the head twitch response produced by 5-methoxy-N1,N1-dimethyltryptamine and p-chloroamphetamine in the mouse.
Psychopharmacology January 1, 1981 C Singleton, C A Marsden 28 citations
In male mice, the head twitch response caused by two different drugs that affect serotonin (5-HT) shows a daily rhythm. Depleting brain serotonin with PCPA increased the response to the direct serotonin receptor agonist 5-MeODMT on days 3 and 5, when serotonin levels were low, but not on day 12 when levels had recovered. PCPA reduced the response to PCA, which releases serotonin from neurons. Under a 12-hour light-dark cycle, the response to the direct agonist peaked near the end of the dark period when serotonin was lowest, while the response to the serotonin-releasing drug peaked in the middle of the light period when serotonin was highest.