Abstract
Introduction Self-administration procedures are the gold standard for investigating the reinforcing effects of drugs. The notable exception to good correspondence between laboratory self-administration studies and human drug taking behavior has historically been the classic hallucinogens. Method The present study used a well-established daily access procedure, followed by a novel intermittent access procedure, to investigate the reinforcing effects of LSD in baboons. Results Rates of self-injection in the daily access procedure were minimal. One baboon self-administered 0.001 mg/kg and a second baboon self-administered 0.0032 mg/kg above vehicle levels, though rates of self-injection were clearly low and neither of the two remaining baboons self-administered any LSD dose tested in the daily access procedure. Rates of self-injection using an intermittent access procedure with discriminative stimuli resulted in two doses of LSD being self-administered above vehicle levels in two of three baboons tested (0.01 and 0.032 mg/kg in one baboon; 0.0032 and 0.01 mg/kg in a second). In addition, the number of self-injections at these doses was higher (range = 3–6 injections) in the intermittent access procedure than in the daily access procedure (range = 1–2 injections). Discussion The present study is the first to demonstrate LSD self-administration in a laboratory animal, and though the results are limited, they indicate intermittent access procedures with discriminative stimuli may provide a reliable and valid method for investigating the reinforcing effects of IV self-administered hallucinogens in laboratory animals. The usefulness of such procedures should be further evaluated in a larger number of subjects.
Original language | English (US) |
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Pages (from-to) | 31-36 |
Number of pages | 6 |
Journal | Journal of Pharmacological and Toxicological Methods |
Volume | 82 |
DOIs | |
State | Published - Nov 1 2016 |
Keywords
- Abuse liability
- Hallucinogen
- Intravenous (IV) self-administration
- Lysergic acid diethylamide (LSD)
- Operant behavior
- Reinforcing effects
ASJC Scopus subject areas
- Toxicology
- Pharmacology