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The effects of developmental nicotine exposure on hypoglossal motoneuron morphology and electrophysiology (871.2)
Author(s) -
Powell Gregory,
Levine Richard,
Fregosi Ralph
Publication year - 2014
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.28.1_supplement.871.2
Subject(s) - excitatory postsynaptic potential , electrophysiology , soma , nicotine , neuroscience , patch clamp , acetylcholine receptor , acetylcholine , nicotinic agonist , biology , chemistry , anatomy , medicine , inhibitory postsynaptic potential , endocrinology , receptor
Developmental nicotine exposure (DNE) is known to have significant effects on motoneuron electrophysiology and morphology. Previous work in hypoglossal motoneurons (XIIMN) of neonatal rats exposed to nicotine in utero has shown decreased excitatory synaptic input, desensitized nicotinic acetylcholine receptors, increased input resistance, a left‐shifted frequency‐current curve as well as increased gain, and preliminary evidence for a decreased soma size. To further examine the effects that DNE has on XIIMNs, we have used whole‐cell patch clamp techniques to record responses to injected sine‐wave currents while neurobiotin passively fills the neurons. Filled cells were visualized using a DAB reaction followed by a detailed morphological reconstruction using the Neurolucida system. Response to sinusoidal current injection was used to record spike firing resonance, which is indicative of spike‐timing precision and variability. These measurements are useful for examining potential changes of the input‐output efficiency of XIIMNs by DNE. Preliminary data indicate significantly increased size of dendritic surface area in DNE cells (n=8 control; 2 DNE). Nicotine exposed cells also appear to be less responsive to sine wave inputs, and more variable in their response as well (n=4 control; 7 DNE). Grant Funding Source : Supported by NIH R01HD071302, AHA 12GRXIT120S0345