Premium
Raphe serotonin neurons: characteristics of central chemoreceptors in situ
Author(s) -
Iceman Kimberly Erin,
Corcoran Andrea E,
Harris Michael B
Publication year - 2010
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.24.1_supplement.1026.7
Subject(s) - raphe , neuroscience , raphe nuclei , serotonin , 5 ht receptor , biology , electrophysiology , brainstem , slice preparation , premovement neuronal activity , serotonergic , receptor , biochemistry
The location and identity of central chemoreceptors is debated, and several different neuronal populations may contribute to central chemosensitivity. Rat raphé serotonin (5HT) neurons, intrinsically sensitive to pH change in vitro, are proposed as chemoreceptors in vivo. Characterization of 5HT neurons as chemoreceptors is refuted, as electrophysiological evidence for chemosensitive 5HT neurons is lacking in vivo. We address this controversy using the unanesthetized juvenile rat in situ perfused decerebrate brainstem preparation. This preparation displays respiratory patterns and reflexes comparable to an intact animal. Through extracellular recording in medullary raphe we demonstrate both chemosensitive and insensitive neurons, including cells with firing patterns expected of 5HT neurons. We also report results of extracellular recording combined with juxtacellular labeling of raphe neurons, identifying neurotransmitter phenotypes of sensitive and insensitive cells. Our results support the presence of chemosensitive 5HT neurons in the raphe in situ. Given the intrinsic chemosensitivity of such neurons in vitro, our data support a role for raphe 5HT neurons as central chemoreceptors in vivo. Supported by NIH 2U54NS041069‐06A1