caa a22 4500 465739091 CHVBK 20180323111803.0 cr unu---uuuuu 170327e19900301xx s 000 0 eng 10.1007/BF02244617 doi (NATIONALLICENCE)springer-10.1007/BF02244617 5HT-2 mediation of acute behavioral effects of hallucinogens in rats [Elektronische Daten] [Lauren Wing, Gregory Tapson, Mark Geyer] In rats tested during their first exposure to a Behavioral Pattern Monitor chamber, acute injections of the 5HT-2 agonists mescaline, quipazine, 2,5-dimethoxy-4-iodoamphetamine (DOI), 2,5-dimethoxy-4-methylamphetamine (DOM), or 2,5-dimethoxy-4-ethylamphetamine (DOET) produced an inhibition of locomotor and investigatory behavior during the first 30 min of the test session. This suppression of exploratory behavior was attenuated when rats were familiarized with the testing chamber prior to the administration of DOI. Hence, as previously observed with both LSD and DOM, 5HT-2 agonists appear to potentiate the normal neophobic reaction to a novel environment. The mixed 5HT-1 and 5HT-2 agonist 5-methoxy-N,N-dimethyltryptamine (5MeODMT) also produced a decrease in activity when animals were tested in the novel environment. However, as previously found with 5HT-1A agonists, this effect was unchanged when animals were tested in the familiar environment and may therefore reflect a generalized sedation. The receptor specificity of these differential effects of 5HT-1 and 5HT-2 agonists in this paradigm was tested by assessing the ability of selective 5HT-2 antagonists to block the effects of the agonists. A dose of the 5HT-2 antagonist ketanserin which had no effect by itself significantly reduced the behavioral effects of mescaline, DOM, and quipazine. Similarly, the selective 5HT-2 antagonist ritanserin blocked the effect of quipazine. In contrast, ketanserin had no significant effect on the suppression of activity produced by the 5HT-1A agonist 8-hydroxy-2(di-n-propylamino)tetralin (8OHDPAT). These results demonstrate that the behavioral effects of 5HT-1 and 5HT-2 agonists can be differentiated both phenomenologically and pharmacologically within a single paradigm. The findings provide further support for the hypothesis that the potentiation of neophobia produced by hallucinogens in rats is attributable to their agonist actions at 5HT-2 receptors. Springer-Verlag, 1990 Serotonin nationallicence Mescaline nationallicence Quipazine nationallicence DOI nationallicence LSD nationallicence Locomotor activity nationallicence Wing Lauren Department of Psychiatry, School of Medicine, T-004, University of California, 92093, San Diego, La Jolla, CA, USA aut Tapson Gregory Department of Psychiatry, School of Medicine, T-004, University of California, 92093, San Diego, La Jolla, CA, USA aut Geyer Mark Department of Psychiatry, School of Medicine, T-004, University of California, 92093, San Diego, La Jolla, CA, USA aut Psychopharmacology Springer-Verlag 100/3(1990-03-01), 417-425 0033-3158 100:3<417 1990 100 213 https://doi.org/10.1007/BF02244617 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF02244617 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Wing Lauren Department of Psychiatry, School of Medicine, T-004, University of California, 92093, San Diego, La Jolla, CA, USA aut NATIONALLICENCE 700 1- Tapson Gregory Department of Psychiatry, School of Medicine, T-004, University of California, 92093, San Diego, La Jolla, CA, USA aut NATIONALLICENCE 700 1- Geyer Mark Department of Psychiatry, School of Medicine, T-004, University of California, 92093, San Diego, La Jolla, CA, USA aut NATIONALLICENCE 773 0- Psychopharmacology Springer-Verlag 100/3(1990-03-01), 417-425 0033-3158 100:3<417 1990 100 213 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer