Dissociations Between the Effects of LSD on Behavior and Raphe Unit Activity in Freely Moving Cats
Michael E. Trulson, Barry L. Jacobs
Science August 3, 1979 DOI: 10.1126/science.451617 via OpenAlex
Summary
AI-generated from the abstractThe hypothesis that hallucinogenic drugs work by suppressing the activity of serotonin-producing neurons in the raphe nuclei was tested by giving LSD to freely moving cats and monitoring both their behavior and raphe neuron activity. Results generally supported the hypothesis, but several mismatches emerged: low LSD doses caused only small decreases in raphe activity yet produced clear behavioral changes; behavioral effects lasted longer than the suppression of raphe firing; and during drug tolerance, raphe neurons remained just as responsive to LSD as they were before tolerance developed.
Study at a glance
| Characteristics | Experimental study Peer reviewed |
|---|---|
| Population | Freely moving cats |
| Intervention | d-lysergic acid diethylamide (LSD) |
| Topics | LSD Serotonin |
| Keywords | Cats Raphe nuclei Dorsal raphe nucleus |
| Citations | 44 |
| Key finding | LSD's behavioral effects in cats did not always align with the suppression of raphe neuron activity, showing dissociations at low doses, in duration, and during tolerance. |
Abstract
The hypothesis that the action of hallucinogenic drugs is mediated by a depression of the activity of brain serotonergic (raphe) neurons was tested by examining the behavioral effects of d -lysergic acid diethylamide (LSD) while studying the activity of raphe neurons in freely moving cats. Although the results provide general support for the hypothesis, there were several important dissociations. (i) Low doses of LSD produced only small decreases in raphe unit activity but significant behavioral changes; (ii) LSD-induced behavioral changes outlasted the depression of raphe unit activity; and (iii) raphe neurons were at least as responsive to LSD during tolerance as they were in the nontolerant condition.