Discriminative stimulus effects of N,N-diisopropyltryptamine.
BACKGROUND
Serotonergic hallucinogens such as (+)-lysergic acid diethylamide (LSD) and dimethyltryptamine (DMT) produce distinctive visual effects, whereas the synthetic hallucinogen N,N-diisopropyltryptamine (DiPT) is known for its production of auditory distortions.


OBJECTIVE
This study compares the discriminative stimulus effects of DiPT to those of visual hallucinogens.


METHODS
Adult male rats were trained to discriminate DiPT (5 mg/kg, 15 min) from saline under a FR10 schedule. A dose-effect and time course of DiPT's discriminative stimulus effects were established. DMT, (-)-2,5-dimethoxy-4-methylamphetamine (DOM), LSD, (±)-methylenedioxymethamphetamine (MDMA), and (+)-methamphetamine were tested for cross-substitution in DiPT-trained animals.


RESULTS
Rats learned to discriminate DiPT from saline in an average of 60 training sessions (30 drug and 30 saline). DiPT (0.5-5 mg/kg) produced dose-dependent increases in drug-appropriate responding (DAR) to 99 % (ED(50) = 2.47 mg/kg). Onset of the discriminative stimulus effects was within 5 min, and the effects dissipated within 4 h. Full substitution for the discriminative stimulus effects of DiPT occurred with LSD, DOM, and MDMA. DMT only partially substituted for DiPT (65 % DAR), whereas (+)-methamphetamine failed to substitute for DiPT (29 % DAR).


CONCLUSIONS
The discriminative stimulus effects of DiPT were similar those of a number of synthetic hallucinogens, only partially similar to those of DMT, but not similar to (+)-methamphetamine. The putative DiPT-induced auditory distortions do not lead to discriminative stimulus effects distinguishable from other hallucinogens.
Department of Pharmacology and Neuroscience, University of North Texas Health Science Center, 3500 Camp Bowie Blvd, Fort Worth, TX 76107-2699, USA.
Theresa M
TM
Carbonaro
Michael J
MJ
Forster
Michael B
MB
Gatch
D004290:DOM 2,5-Dimethoxy-4-Methylamphetamine / Q000494:pharmacology; D000818:Animals; D004193:Discrimination Learning / Q000187:drug effects*; D004305:Dose-Response Relationship, Drug; D006213:Hallucinogens / Q000494:pharmacology*; D008238:Lysergic Acid Diethylamide / Q000494:pharmacology; D008297:Male; D008694:Methamphetamine / Q000494:pharmacology; D018817:N-Methyl-3,4-methylenedioxyamphetamine / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D014363:Tryptamines / Q000494:pharmacology*
D006213:Hallucinogens; D014363:Tryptamines; C033695:N,N-diisopropyltryptamine; D004290:DOM 2,5-Dimethoxy-4-Methylamphetamine; D008694:Methamphetamine; D008238:Lysergic Acid Diethylamide; D018817:N-Methyl-3,4-methylenedioxyamphetamine