Tolerance and limited cross-tolerance to the effects of N, N-dimethyltryptamine (DMT) and lysergic acid diethylamide-25 (LSD) on food-rewarded bar pressing in the rat.
Journal of Pharmacology and Experimental Therapeutics June 1, 1976 Beverly Kovacic, E. F. Domino 33 citations
LSD and DMT disrupt food-rewarded bar pressing in rats in a dose-dependent manner. Adult male Holtzman rats trained to press a bar for milk on a fixed-ratio schedule received daily injections of DMT (3.2 or 10 mg/kg) every 2 hours for 21 days. Bar pressing worsened progressively during the first week, with the 10 mg/kg group ceasing to press by day 6, but gradually recovered with continued injections. Rats given 3.2 mg/kg DMT showed cross-tolerance to LSD (0.1 mg/kg). Conversely, rats made tolerant to LSD over 21 days did not initially show cross-tolerance to 10 mg/kg DMT, but after additional LSD injections until complete tolerance, they displayed cross-tolerance to 3.2 mg/kg DMT.