We read with interest the study of ketamine psychedelic and analgesic effects by Olofsen et al.1 and the accompanying editorial by Mashour.2 In both articles, the authors refer to the “dissociative” effects of ketamine. Corssen and Domino3 originally used the term “dissociative” in 1966 to describe “patients and subjects who, during recovery from CI-581 [ketamine], felt as though they were in...
A fixed-ratio schedule of water reinforcement (FR-10) was used to examine the relative contributions of pharmacological and behavioral mechanisms in the development of tolerance to the disruptive effects of LSD and mescaline in the rat. Rats treated daily with LSD or mescaline before operant testing developed tolerance to the impairement of responding, while rats treated daily after each...