RT Journal Article
SR Electronic
T1 Heterogeneity of Nicotinic Receptor Class and Subunit mRNA Expression among Individual Parasympathetic Neurons from Rat Intracardiac Ganglia
JF The Journal of Neuroscience
JO J. Neurosci.
FD Society for Neuroscience
SP 586
OP 596
DO 10.1523/JNEUROSCI.17-02-00586.1997
VO 17
IS 2
A1 Kevin Poth
A1 Thomas J. Nutter
A1 Javier Cuevas
A1 Michael J. Parker
A1 David J. Adams
A1 Charles W. Luetje
YR 1997
UL http://www.jneurosci.org/content/17/2/586.abstract
AB Neurons have the potential to form thousands of distinct neuronal nicotinic receptors from the eight α and three β subunits that currently are known. In an effort to determine how much of this potential complexity is realized among individual neurons, we examined the nicotinic pharmacological and biophysical properties and receptor subunit mRNA expression patterns in individual neurons cultured from rat epicardial ganglia. Analysis of the whole-cell pharmacology of these neurons showed a diversity of responses to the agonists acetylcholine, nicotine, cytisine, and 1,1-dimethyl-4-phenylpiperazinium, suggesting that a heterogeneous population of nicotinic receptor classes, or subtypes, is expressed by individual neurons. Single-channel analysis demonstrated three distinct conductances (18, 24, and 31 pS), with patches from different neurons containing different combinations of these channel classes. We used single-cell RT-PCR to examine nicotinic acetylcholine receptor (nAChR) subunit mRNA expression by individual neurons. Although mRNAs encoding all eight neuronal nAChR subunits for which we probed (α2–α5, α7, β2–β4) were present in multicellular cultures, we found that individual epicardial neurons express distinct subsets of these nAChR subunit mRNAs. These results suggest that individual epicardial neurons express distinct arrays of nAChR subunits and that these subunits may assemble into functional receptors with distinct and variable subunit composition. This variable receptor subunit expression provides an explanation for the diversity of pharmacological and single-channel responses we have observed in individual neurons.