Effects of repeated treatment with 1-(2,5-dimethoxy-4-iodophenyl)-2-aminopropane (DOI) on the autoregulatory control of dorsal raphe 5-HT neuronal firing and cortical 5-HT release.
These experiments were designed to examine the effects of repeated 1-(2,5-dimethoxy-4-iodophenyl)-2-aminopropane (DOI) treatment on the autoregulatory control of cortical 5-HT release and dorsal raphe nucleus (DRN) 5-HT neuronal cell firing. Repeated DOI treatment decreased the behavioural responsiveness (wet-dog shakes) of 5-HT2 receptors and attenuated the inhibitory effects of the 5-HT1A receptor agonist, 8-OH-DPAT (8-hydroxy-2-(di-n-propylamino)tetralin), on both cortical 5-HT release and DRN 5-HT neuronal firing. In contrast, the inhibitory effect of acute DOI on cortical 5-HT release and DRN 5-HT neuronal firing was unaffected by repeated DOI treatment. The results demonstrate that changes in the responsiveness of 5-HT2 receptor function may influence the responsiveness of presynaptic 5-HT1A receptors regulating 5-HT neuronal function. The results also provide further evidence that the inhibition of cortical 5-HT release and DRN 5-HT neuronal firing produced by DOI is not mediated by 5-HT2 receptor activation.
Kidd
E J
EJ
Department of Physiology and Pharmacology, Medical School Queen's Medical Centre, Nottingham, U.K.
Garratt
J C
JC
Marsden
C A
CA
D017371:8-Hydroxy-2-(di-n-propylamino)tetralin; D000662:Amphetamines / Q000494:pharmacology*; D000704:Analysis of Variance; D000818:Animals; D002540:Cerebral Cortex / Q000187:drug effects / Q000378:metabolism*; D004334:Drug Administration Schedule; D004594:Electrophysiology; D008297:Male; D009043:Motor Activity / Q000187:drug effects; D009474:Neurons / Q000187:drug effects / Q000502:physiology; D011903:Raphe Nuclei / Q000187:drug effects / Q000502:physiology*; D051381:Rats; D011919:Rats, Inbred Strains; D011985:Receptors, Serotonin / Q000378:metabolism; D012701:Serotonin / Q000378:metabolism*; D012702:Serotonin Antagonists / Q000494:pharmacology*; D013764:Tetrahydronaphthalenes / Q000494:pharmacology
D000662:Amphetamines; D011985:Receptors, Serotonin; D012702:Serotonin Antagonists; D013764:Tetrahydronaphthalenes; D012701:Serotonin; D017371:8-Hydroxy-2-(di-n-propylamino)tetralin; C015952:4-iodo-2,5-dimethoxyphenylisopropylamine