Neuronal nicotinic acetylcholine receptors in rat trigeminal ganglia.
The application of nicotine to the various epithelia served by the trigeminal nerve produces irritation and/or pain by activating neuronal nicotinic acetylcholine receptors (NnAChRS) in sensory neurons. In this study the NnAChRs were identified in rat trigeminal ganglia (TG) using RT-PCR and immunocytochemistry. With RT-PCR the subunits of NnAChRs in rat TG were determined, and with immunocytochemistry the localization of three prominent subunits (alpha 7, alpha 4 and beta 2) were localized in intact TG neurons. The relative abundance of the alpha and beta subunits were: alpha 7 approximately alpha 3 > alpha 6 > alpha 4 approximately alpha 5 > alpha 9 > or = alpha 2, and beta 2 approximately beta 3 > beta 4. This is the first report of the alpha 9 subunit in TG. Immunohistochemical studies revealed that almost all TG neurons contained alpha 7-LI and alpha 4-LI, and that 85% had beta 2-LI. For these three subunits much of the label was internalized. Immunocytochemical studies using antibodies raised against chick alpha 8 subunits did not specifically label rat TG. These data reveal that rat TG neurons contain the entire spectrum of mammalian NnAChR subunits.
Liu
L
L
Department of Neurobiology, Duke University Medical Center, Durham, NC 27710, USA.
Chang
G Q
GQ
Jiao
Y Q
YQ
Simon
S A
SA
D000818:Animals; D015342:DNA Probes; D005260:Female; D015870:Gene Expression / Q000502:physiology; D008297:Male; D009443:Neuritis / Q000150:complications / Q000503:physiopathology*; D009475:Neurons, Afferent / Q000737:chemistry*; D010146:Pain / Q000209:etiology / Q000503:physiopathology; D012333:RNA, Messenger / Q000032:analysis; D051381:Rats; D011978:Receptors, Nicotinic / Q000235:genetics*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014278:Trigeminal Nuclei / Q000737:chemistry* / Q000166:cytology*; D064569:alpha7 Nicotinic Acetylcholine Receptor
C579165:Chrna7 protein, rat; D015342:DNA Probes; D012333:RNA, Messenger; D011978:Receptors, Nicotinic; D064569:alpha7 Nicotinic Acetylcholine Receptor