Abstract
The effects of chronic nicotine exposure on chemosensitivity of medullary 5‐HT neurons
The FASEB journal, Vol.26(S1)
04/2012
DOI: 10.1096/fasebj.26.1_supplement.1090.8
Abstract
Abstract only 5‐HT neurons are chemoreceptive and involved in respiratory control. SIDS has been linked to brainstem 5‐HT abnormalities, fetal nicotine exposure and impaired responses to changes in O 2 and CO 2 . We tested the hypothesis that nicotine may increase the risk of SIDS by impairing 5‐HT neuronal function. We used perforated patch clamp to record changes in firing rate (FR) in response to acidosis and to acute nicotine exposure of 5‐HT neurons cultured for >12 days from the medullary raphé of 2 day old mice. An osmotic minipump was implanted into pregnant mice at E10 supplying 6 or 60 mg kg −1 day −1 of nicotine, and/or nicotine was subsequently added to the cultures at 0.05 μM or 0.5 μM respectively. Neurons were bathed in aCSF at 5% CO 2 (pH 7.4) containing GABA and glutamate receptor blockers until FR stabilized at 1 Hz, then were exposed to two‐ 3 min episodes of 9% CO 2 (pH 7.2) with wash out each time. This was then repeated with aCSF containing 10μM nicotine. Neurons exposed chronically to nicotine (n=92) exhibited a reduced response to acute nicotine exposure and to acidosis. These effects were found to be attributed to both prenatal and postnatal exposure and were more pronounced in mature neurons and in neurons exposed to a higher dose of nicotine. In the developing neonate such changes in 5‐HT neuronal function and chemoreception may impair responses to changes in O 2 and CO 2 and potentially increase the incidence of SIDS.
Details
- Title: Subtitle
- The effects of chronic nicotine exposure on chemosensitivity of medullary 5‐HT neurons
- Creators
- Joanne Avraam - University of IowaYuanming Wu - University of IowaGeorge B Richerson - University of Iowa
- Resource Type
- Abstract
- Publication Details
- The FASEB journal, Vol.26(S1)
- DOI
- 10.1096/fasebj.26.1_supplement.1090.8
- ISSN
- 0892-6638
- eISSN
- 1530-6860
- Language
- English
- Date published
- 04/2012
- Academic Unit
- Molecular Physiology and Biophysics; Neurosurgery; Neurology; Iowa Neuroscience Institute
- Record Identifier
- 9984629156602771
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