Tolerance to the hypothermic effects of 9-tetrahydrocannabinol as a function of age in the chicken

1. (-)-Delta(9)-Tetrahydrocannabinol was administered to chicks (Gallus domesticus) of various ages and body temperature and tolerance to the hypothermic effects of the drug were examined as a function of age.2. The hypothermic effects were found to be greater in neonatal than older animals and likewise tolerance took longer to develop in younger chicks.3. The rate of tolerance development, however, could be increased in the neonate by preadministration of a high dose of the drug.