Premium
Developmental Nicotine Exposure Alters The Respiratory Frequency Response to Muscarine
Author(s) -
Wollman Lila,
Haggerty Jarl,
Pilarski Jason,
Levine Richard,
Fregosi Ralph
Publication year - 2015
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.29.1_supplement.1032.15
Subject(s) - muscarine , muscarinic acetylcholine receptor , nicotinic agonist , acetylcholine , neuroscience , acetylcholine receptor , nicotine , bursting , brainstem , chemistry , medulla , endocrinology , medicine , receptor , biology
Prenatal nicotine exposure with continued exposure through breast milk over the first week of life (developmental nicotine exposure, DNE) alters development of the brainstem circuits that control breathing. Previous work has shown that DNE desensitizes nicotinic acetylcholine receptors (nAChRs) and alters the respiratory motor response to exogenous nicotine in neonatal rats. In the brainstem‐spinal cord (BSSC) split‐bath preparation, nicotine applied to the medullary compartment increases the frequency of respiratory related bursting recorded from the fourth cervical ventral root (C4VR), but this effect is markedly blunted by DNE. Because ACh is the endogenous ligand for both nAChRs and muscarinic acetylcholine receptors (mAChRs), and mAChRs are expressed on PreBotzinger neurons, we hypothesized that DNE also alters muscarinic modulation of C4VR frequency in this system. In neonatal rats, postnatal day 0‐6, 1 mM muscarine, a mAChR agonist, applied to the medullary compartment in the BSSC split‐bath preparation increased burst frequency recorded from C4VR in 4/4 control animals and, in some cases, the pattern of bursting became irregular. Muscarine applied to the medulla decreased burst frequency in 4/4 DNE animals. These preliminary data show that chronic stimulation of nAChRs also alters the development of muscarinic synaptic transmission by yet to be determined mechanisms.