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Activation of 5‐HT 2 receptors enhances the release of acetylcholine in the prefrontal cortex and hippocampus of the rat
Author(s) -
Nair Sunila G.,
Gudelsky Gary A.
Publication year - 2004
Publication title -
synapse
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.809
H-Index - 106
eISSN - 1098-2396
pISSN - 0887-4476
DOI - 10.1002/syn.20054
Subject(s) - prefrontal cortex , microdialysis , hippocampus , agonist , acetylcholine , chemistry , medicine , endocrinology , neuroscience , receptor , extracellular , psychology , biochemistry , cognition
Abstract The role of 5‐HT 2 receptors in the regulation of acetylcholine (ACh) release was examined in the medial prefrontal cortex and dorsal hippocampus using in vivo microdialysis. The 5‐HT 2A/2C agonist ±1‐(2,5‐dimethoxy‐4‐iodophenyl) ‐2‐ aminopropane hydrochloride (DOI) (1 and 2 mg/kg, i.p.) significantly increased the extracellular concentration of ACh in both brain regions, and this response was attenuated in rats treated with the 5‐HT 2A/2B/2C antagonist LY‐53,857 (3 mg/kg, i.p.). Treatment with LY‐53,857 alone did not significantly alter ACh release in either brain region The 5‐HT 2C agonist 6‐chloro‐2‐(1‐piperazinyl)‐pyrazine) (MK‐212) (5 mg/kg, i.p.) significantly enhanced the release of ACh in both the prefrontal cortex and hippocampus, whereas the 5‐HT 2 agonist mescaline (10 mg/kg, i.p.) produced a 2‐fold increase in ACh release only in the prefrontal cortex. Intracortical, but not intrahippocampal, infusion of DOI (100 μM) significantly enhanced the release of ACh, and intracortical infusion of LY‐53,857 (100 μM) significantly attenuated this response. These results suggest that the release of ACh in the prefrontal cortex and hippocampus is influenced by 5‐HT 2 receptor mechanisms. The increase in release of ACh induced by DOI in the prefrontal cortex, but not in the hippocampus, appears to be due to 5‐HT 2 receptor mechanisms localized within this brain region. Furthermore, it appears that the prefrontal cortex is more sensitive than the dorsal hippocampus to the stimulatory effect of 5‐HT 2 agonists on ACh release. Synapse 53:202–207, 2004. © 2004 Wiley‐Liss, Inc.