REVERSAL LEARNING ENHANCED BY LYSERGIC ACID DIETHYLAMIDE (LSD): CONCOMITANT RISE IN BRAIN 5‐HYDROXYTRYPTAMINE LEVELS
Alan R. King, Ian L. Martin, Kathleen Melville
British Journal of Pharmacology November 1, 1974 DOI: 10.1111/j.1476-5381.1974.tb08611.x (opens in new tab) via OpenAlex
Summary
AI-generated from the abstractLow doses of LSD (12.5–50 μg/kg) consistently made rats faster at learning a brightness discrimination reversal task. A similar compound, BOL-148, which has the same anti-serotonin effects outside the brain but lacks LSD's hallucinogenic properties, had no effect on learning at a comparable dose (25 μg/kg). LSD, but not BOL-148, slightly raised serotonin levels in the brain, while neither drug changed brain catecholamine levels at 25 μg/kg. These results suggest that LSD's effect on learning is tied to its specific psychoactive properties, not just its peripheral anti-serotonin activity.
Study at a glance
| Characteristics | Experimental study Peer reviewed |
|---|---|
| Population | Rats |
| Intervention | LSD |
| Dose | 12.5–50 μg/kg (LSD), 25 μg/kg (BOL-148) |
| Topics | LSD Serotonin |
| Keywords | Concomitant Pharmacology Neuroscience Hallucinogen |
| Citations | 38 |
| Key finding | LSD, but not its non-hallucinogenic analogue BOL-148, facilitated learning of a brightness discrimination reversal and slightly increased brain serotonin levels in rats. |
Abstract
Small doses of lysergic acid diethylamide (LSD) (12.5–50 μg/kg) consistently facilitated learning of a brightness discrimination reversal. 2‐Bromo‐lysergic acid diethylamide (BOL‐148), a structural analogue of LSD, with similar peripheral anti‐5‐hydroxytrypamine activity but no psychotomimetic properties, had no effect in this learning situation at a similar dose (25 μg/kg). LSD, but not BOL‐148, caused a small but significant increase in brain 5‐hydroxytryptamine levels, but had no effect on the levels of catecholamines in the brain at 25 μg/kg.