Hoffmann, R. A wiki for the life sciences where authorship matters. Nature Genetics (2008)

Editor

Personal info

View

About

Terms

Javascript disabled

Please enable Javascript support in your browser to use this application.

Instructions on how to enable JavaScript on different browsers can be found here: http://www.google.com/support/bin/answer.py?answer=23852.

[edit this page]

McCall, R.B.

Neurophysiological effects of hallucinogens on serotonergic neuronal systems.

Low intravenous doses of the hallucinogen d-lysergic acid diethylamide (LSD) markedly suppress the discharge of serotonin (5-HT)-containing neurons in the dorsal raphe nucleus of the rat. Microiontophoretically applied LSD also inhibits the firing of 5-HT neurons, indicating that the inhibitory effect is mediated directing on 5-HT neurons. Forebrain neurons receiving a major serotonergic input are relatively insensitive to LSD. Other indole hallucinogens (i.e., psilocin, dimethyltryptamine, and 5-methoxydimethyltryptamine) also preferentially inhibit raphe firing as compared to postsynaptic forebrain neurons. These observations led to the hypothesis that hallucinogens produce their psychoactive effects by acting preferentially upon 5-HT autoreceptors in the dorsal raphe allowing postsynaptic neurons to escape from the tonic inhibitory action of 5-HT neurons. However, problems exist with the concept that hallucinogens produce their psychoactive effects by disinhibiting postsynaptic neurons. First, the time course of the behavioral and neuronal effects of LSD do not correlate. Second, 5-HT neurons do not become tolerant to the inhibitory actions of LSD. Third, the hallucinogen mescaline fails to directly inhibit 5-HT neurons. Finally, the nonhallucinogen lisuride markedly suppresses the discharges of 5-HT neurons. These observations suggest that postsynaptic actions of hallucinogens may be of prime importance in producing their psychedelic effects. Evidence is presented to suggest that the hallucinogens may act postsynaptically to sensitize both serotonergic and noradrenergic receptors. It is suggested that a mechanism of receptor sensitization, in distinction to disinhibition, might account for the altered perceptual reactivity produced by these drugs.[1]

References

Neurophysiological effects of hallucinogens on serotonergic neuronal systems. McCall, R.B. Neuroscience and biobehavioral reviews. (1982) [Pubmed]

Annotations and hyperlinks in this abstract are from individual authors of WikiGenes or automatically generated by the WikiGenes Data Mining Engine. The abstract is from MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.About WikiGenes Open Access Licence Privacy Policy Terms of Use apsburg

The world's first wiki where authorship really matters (Nature Genetics, 2008). Due credit and reputation for authors. Imagine a global collaborative knowledge base for original thoughts. Search thousands of articles and collaborate with scientists around the globe.