First Author | Lazarenko RM | Year | 2011 |
Journal | Respir Physiol Neurobiol | Volume | 175 |
Issue | 2 | Pages | 283-7 |
PubMed ID | 21145990 | Mgi Jnum | J:251342 |
Mgi Id | MGI:6100360 | Doi | 10.1016/j.resp.2010.12.003 |
Citation | Lazarenko RM, et al. (2011) Orexin A activates retrotrapezoid neurons in mice. Respir Physiol Neurobiol 175(2):283-7 |
abstractText | The retrotrapezoid nucleus (RTN), located at the ventral surface of the medulla oblongata, contains glutamatergic Phox2b-expressing interneurons that have central respiratory chemoreceptor properties. RTN also operates as a relay for hypothalamic pathways that regulate breathing, one of which probably originates from the orexinergic neurons (Dias et al., 2009. J. Physiol. 587, 2059-2067). The present study explores this hypothesis at the cellular level. Using immunohistochemistry in adult Phox2b-eGFP transgenic mice, we demonstrate the presence of numerous close appositions between orexin-containing axonal varicosities and RTN chemoreceptor neurons. Using electrophysiological recordings in slices from neonatal (P6-P10) Phox2b-eGFP mice, we show that orexin A produces a robust dose-dependent excitation of the acid-sensitive RTN neurons (ED(50) approximately 250nM). These data support the idea that RTN neurons are a point of convergence for several groups of CNS neurons that contribute to respiratory chemoreflexes, now including serotonergic and orexinergic neurons. |