Premium
Astrocytic calcium signals induced by neuromodulators via functional metabotropic receptors in the ventral respiratory group of neonatal mice
Author(s) -
Härtel Kai,
Schnell Christian,
Hülsmann Swen
Publication year - 2009
Publication title -
glia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.954
H-Index - 164
eISSN - 1098-1136
pISSN - 0894-1491
DOI - 10.1002/glia.20808
Subject(s) - biology , metabotropic glutamate receptor , neuroscience , respiratory system , metabotropic receptor , calcium , receptor , glutamate receptor , respiratory center , medicine , anatomy , biochemistry
A controlled, periodic exchange of air between lungs and atmosphere requires a neuronal rhythm generated by a network of neurons in the ventral respiratory group (VRG) of the brainstem. Glial cells, e.g. astrocytes, have been shown to be supportive in stabilizing this neuronal activity in the central nervous system during development. In addition, a variety of neuromodulators including serotonin (5‐HT), Substance P (SP), and thyrotropin‐releasing hormone (TRH) stimulate respiratory neurons directly. If astrocytes in the VRG, like their neuronal neighbors, are also directly stimulated by neuromodulators, they might indirectly affect the respiratory neurons and consequently the respiratory rhythm. In the present study, we provide support for this concept by demonstrating expression of NK1‐R, TRH‐R, and 5‐HT 2 ‐R in astrocytes of the VRG with immunohistochemistry. Additionally, we showed that the external application of the neuromodulators 5‐HT, SP, and TRH activate calcium transients in VRG astrocytes. Consequently, we postulate that in the VRG of the neonatal mouse, neuromodulation by SP, TRH, and serotonin also involves astrocytic calcium signaling. © 2008 Wiley‐Liss, Inc.