Age dependence of 5-methoxytryptamine-induced hindlimb scratching in rats

The influence of age on hindlimb scratching induced in rats by the serotonin agonist, 5-methoxytryptamine (5-MeOT), was studied. The 5-MeOT-induced scratching was strongest in 30-day-old rats and least in 90-day-old rats. Sex hormones do not play a role in these differences since treatment of young male rats with testosterone propionate did not change the scratching response. The same age dependence was found for female rats as for males.