Elsevier

Neuroscience Letters

Volume 139, Issue 2, 25 May 1992, Pages 243-248
Neuroscience Letters

Serotonergic excitatory drive to hypoglossal motoneurons in the decerebrate cat

https://doi.org/10.1016/0304-3940(92)90563-MGet rights and content
Under a Creative Commons license
open archive

Abstract

In decerebrate, paralyzed, vagotomized and artificially ventilated cats, serotonin (5-HT) and its analogues, microinjected into the hypoglossal (XII) motor nucleus, altered the activity of the genioglossal branch of XII nerve. 5-HT, carboxamidotryptamine malcate (5-CT) and DOI (1–5 mM) increased the activity by over 200%. Methysergide reversed this increase. Methysergide, mianserin, or ketanserin (100–250 nl, 1 mM) reduced the spontaneous hypoglossal activity by 20–50%. Buspirone, 8-OH-DPAT and (−)-propranolol were without effect. Thus, 5-HT provides a substantial tonic excitatory drive to XII motoneurons. The 5-HT receptors involved are likely to be type 1C or 2, but uncertainty regarding the affinity profiles of the drugs used in in vivo conditions in the cat precludes a definite identification.

Keywords

Serotonin
Hypoglossal motoneuron
Genioglossal motoneuron
Decerebrate cat
Sleep apnea
Respiration
Upper airway
Microinjection

Cited by (0)