Regulation of noradrenergic coerulean neuronal firing mediated by 5-HT2 receptors: Involvement of the prepositus hypoglossal nucleus

doi:10.1016/0028-3908(91)90028-A

Neuropharmacology

Volume 30, Issue 12, Part A, December 1991, Pages 1309-1318

https://doi.org/10.1016/0028-3908(91)90028-A Get rights and content

Abstract

Previous studies have indicated a 5-HT₂-mediated inhibitory influence on unit activity in the locus coeruleus. In the present work, attempts were made to determine which area(s) of the brain is (are) involved in this effect: (1) Microiontophoretic application of serotoninergic compounds (quipazine, ketanserin, RU 24969 (Roussel Uclaf), 8-hydroxy-2(di-n-propylamino) tetralin (8-OH-DPAT), metergoline, serotonin) in the locus coeruleus, did not alter the coerulean discharge. Local microinjection of quipazine or ketanserin in the area of the locus coeruleus, as well as in one of its major afferents, the prepositus hypoglossi, had no effect on the unit activity in the locus coeruleus.

1.
(2) Section of the forebrain, caudal to the frontal cortex (rich in 5-HT₂ receptors), did not modify the effects on coerulean activity of quipazine-ketanserin injected systemically: quipazine induced an inhibition which was reversed by ketanserin. In contrast, these effects were significantly reduced after the bilateral or contralateral lesion of the prepositus hypoglossi.

It is concluded that the prepositus hypoglossal nucleus is part of the network responsible for the 5-HT₂-mediated control of unit activity in the locus coeruleus.

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Regulation of noradrenergic coerulean neuronal firing mediated by 5-HT2 receptors: Involvement of the prepositus hypoglossal nucleus

Abstract

Neurosci. Lett.

Brain Res.

Neurochem. Int.

Eur. J. Pharmac.

Brain Res. Bull.

Neuropharmacology

Eur. J. Pharmac.

Neuroscience

TIPS Rev.

Brain Res. Bull.

Brain Res.

Brain Res.

Brain Res.

Eur. J. Pharmac.

Regulation of noradrenergic coerulean neuronal firing mediated by 5-HT₂ receptors: Involvement of the prepositus hypoglossal nucleus