Early preclinical studies of discriminable sedative and hallucinogenic drug effects.
BACKGROUND
One important technique in behavioral pharmacology is to train laboratory animals to discriminate between a psychoactive drug effect and a nondrug condition. Tests with different drugs have identified several categories of drugs that have different discriminable effects.


OBJECTIVE
The two authors describe and discuss the early research on discriminable effects of sedative and hallucinogenic drugs and their acquaintance with each other at Yale University prior to their early and frequent publications on discriminable drug effects. Herb Barry studied sedative drugs primarily and Jim Appel studied hallucinogenic drugs.


RESULTS
Sedative drugs include ethyl alcohol, barbiturates, and benzodiazepines. Their discriminable effects are largely attributable to the activation of an inhibitory neurotransmitter, gamma-amino butyric acid. Alcohol has the most pervasive effect in accordance with the high dose required to alter behavior. Hallucinogenic drugs include lysergic acid diethylamide and mescaline. They increase the activity of the neurotransmitter 5-hydroxytryptamine and, perhaps, dopamine in the central nervous system (CNS). In spite of their relatively low concentrations in the brain, both of these neurotransmitters have many important behavioral effects.


CONCLUSIONS
Various sedative drugs cause a discriminable decrease in the function of the CNS. Different types of sedatives can be discriminated from each other. Indole and phenylethylamine hallucinogens have potent discriminative stimulus properties, which are related to the actions of biogenic amine neurotransmitters in the CNS.
Barry
Herbert
H
University of Pittsburgh, Pittsburgh, PA, USA. barryh@pitt.edu
Appel
James B
JB
D000818:Animals; D003216:Conditioning, Operant / Q000187:drug effects*; D004192:Discrimination, Psychological / Q000187:drug effects*; D004353:Drug Evaluation, Preclinical / Q000379:methods*; D006213:Hallucinogens / Q000008:administration & dosage / Q000494:pharmacology*; D006993:Hypnotics and Sedatives / Q000008:administration & dosage / Q000494:pharmacology*; D011600:Psychopharmacology / Q000379:methods*
D006213:Hallucinogens; D006993:Hypnotics and Sedatives