Davies, Michael, Wilkinson, Lawrence Stephen ORCID: https://orcid.org/0000-0002-9337-6124 and Roberts, Malcolm H.T. 1988. Evidence for excitatory 5-HT2-receptors on rat brainstem neurones. British Journal of Pharmacology 94 (2) , pp. 483-491. 10.1111/j.1476-5381.1988.tb11551.x |
Abstract
1 The technique of microiontophoresis was used to investigate the identity of the receptor mediating the excitatory effects of 5-hydroxytryptamine (5-HT) upon neurones in the midline of the medullary brainstem of the rat in vivo. 2 The 5-HT1-like receptor agonists 5-carboxamidotryptamine (5-CT) and 8-hydroxy-2-(di-n-propylamino) tetralin (8-OH-DPAT) failed to excite the majority of neurones excited by 5-HT. The mobilities of 5-CT and 8-OH-DPAT when tested in vitro were found not to differ significantly from that of 5-HT, suggesting that the lack of effect of these agonists was not due to a lower rate of release from the microelectrodes. 3 The excitatory responses to 5-HT were attenuated by the 5-HT2-receptor antagonists ketanserin and methysergide when applied microiontophoretically or administered intravenously (0.3 and 1 mg kg−1 respectively). Excitatory responses to glutamate and noradrenaline were not reduced. 4 The 5-HT3-receptor antagonist MDL 72222 failed to attenuate selectively the excitatory response to 5-HT when applied either by microiontophoresis or administered intravenously (1 mg kg−1). 5 Microiontophoretic application of the α1-adrenoceptor antagonist prazosin did not attenuate excitatory responses to either 5-HT or noradrenaline. Intravenously administered prazosin (0.8 mg kg−1) also failed to attenuate excitatory responses to 5-HT, but did block excitatory responses to noradrenaline. 6 These results suggest that 5-HT2-receptors, but not 5-HT1-like receptors, 5-HT3-receptors or α1-adrenoceptors, are involved in the excitatory response of midline medullary neurones to 5-HT.
Item Type: | Article |
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Date Type: | Publication |
Status: | Published |
Schools: | MRC Centre for Neuropsychiatric Genetics and Genomics (CNGG) Medicine Neuroscience and Mental Health Research Institute (NMHRI) Psychology |
Subjects: | R Medicine > R Medicine (General) |
Publisher: | Nature Publishing Group |
ISSN: | 0007-1188 |
Last Modified: | 31 Oct 2022 10:36 |
URI: | https://orca.cardiff.ac.uk/id/eprint/85459 |
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