title: Cumulative alterations in rat behavior during continuous administration of LSD or mescaline: absence of tolerance?
abstract: Male hooded rats were observed for 6 days following implantation with slow-release subcutaneous pellets containing LSD, mescaline, or control vehicle solution. In animals housed in isolation cages, continuous hallucinogen administration resulted in a gradual increase in head twitches and catatonic postures which peaked 3--4 days after pellet implantation and then declined. In animals housed in social colonies, there were also delayed increases in behavior following hallucinogen-pellet implantation, but these principally involved social behaviors such as fighting by mescaline-treated animals and social grooming by LSD-treated animals. This finding of gradual and cumulative effects of continuous hallucinogen administration contrasts with the usual finding of a rapid tolerance to hallucinogens following repeated injections.
mesh_terms: D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects*; D003692:Delayed-Action Preparations; D004361:Drug Tolerance; D008238:Lysergic Acid Diethylamide / Q000494:pharmacology*; D008297:Male; D008635:Mescaline / Q000494:pharmacology*; D009043:Motor Activity / Q000187:drug effects; D051381:Rats; D013216:Reflex, Startle / Q000187:drug effects; D012934:Social Isolation
chemical_list: D003692:Delayed-Action Preparations; D008238:Lysergic Acid Diethylamide; D008635:Mescaline