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Carbachol injections in the nucleus pontis oralis elicit REM sleep‐like depression of XII nerve activity in the rat in situ perfused working heart‐brainstem preparation (WHBP)
Author(s) -
Brandes Ivo F.,
Stettner Georg,
Kubin Leszek,
Dutschmann Mathias
Publication year - 2009
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.23.1_supplement.960.9
Subject(s) - carbachol , pons , brainstem , anesthesia , medicine , anatomy , chemistry , stimulation
Patients with obstructive sleep apnea suffer from nocturnal episodes of upper airway collapse and hypoxia that is most severe during rapid‐eye‐movement sleep (REMS). The XII activity is diminished and the upper airway muscle tone is reduced. To study the central neural mechanisms of REMS, in vivo pharmacological models have been used (Kubin, 2001). To test whether upper airway motor tone depression can be also elicited in the in situ rat WHBP, carbachol (25‐50 nl, 10mM) was injected into the pons in n=33 WHBPs while recording XII and phrenic nerve activities (PNA). In 23 preparations, depression of XII nerve activity lasting 16‐24 min occurred within 142 s ± 26. The depressant episodes could be elicited repeatedly by injections at the same site at >30 min intervals. Histological analysis revealed effective injection sites in the nucleus pontis oralis, Bregma ‐8.16 to ‐8.76, (Paxinos and Watson, 2005). Ineffective injection sites were either located in the nucleus pontis caudalis, were too ventral or too lateral. Only carbachol injections into the nucleus pontis oralis trigger REMS like alterations of the breathing pattern in the WHBP. Funded by BCCN Göttingen and HL‐47600.