Expression of the sodium channel Na(v)1.2 in chemically identified myenteric neurons in the guinea pig.
Our purpose was to identify Na(v)1.2-expressing myenteric neurons of the small and large intestine of the guinea pig by using antibodies directed against Na(v)1.2 and selected neurochemical markers. Na(v)1.2-like immunoreactivity (-li) co-localized with immunoreactivity for choline acetyltransferase in all regions, representing 45%-67% of Na(v)1.2-positive neurons. Na(v)1.2-li co-localized with immunoreactivity for the neural form of nitric oxide synthase more frequently in the colon (20% of neurons exhibiting Na(v)1.2-li) than in the ileum (8%). Co-localization of Na(v)1.2-li with immunoreactivity for a form of neurofilament (NF145) was infrequently observed in the ileum and colon. Enkephalin-immunoreactive cell bodies co-localized with Na(v)1.2-li in all regions. Few myenteric cell bodies immunoreactive for neuropeptide Y were observed in the ileum, but all co-localized with Na(v)1.2-li. This and our previous data suggest that Na(v)1.2 is widely expressed within the guinea pig enteric nervous system, including the three main classes of myenteric neurons (sensory, motor, and interneurons), and is involved in both excitatory and inhibitory pathways. Notable exceptions include the excitatory motor neurons to the longitudinal smooth muscle, the ascending interneurons of the ileum, and the myenteric neurons immunoreactive for NF145, few of which are immunoreactive for Na(v)1.2.
Bartoo
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AC
Program in Neuroscience, Department of Veterinary and Comparative Anatomy, Pharmacology and Physiology, Washington State University, Pullman, WA 99164-6520, USA.
Sprunger
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LK
Schneider
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DA
D000818:Animals; D002795:Choline O-Acetyltransferase / Q000378:metabolism; D004745:Enkephalins / Q000378:metabolism; D015870:Gene Expression; D006168:Guinea Pigs; D009197:Myenteric Plexus / Q000378:metabolism*; D009474:Neurons / Q000378:metabolism*; D009478:Neuropeptide Y / Q000378:metabolism; D052248:Nitric Oxide Synthase Type I / Q000378:metabolism; D015222:Sodium Channels / Q000378:metabolism*
D004745:Enkephalins; D009478:Neuropeptide Y; D015222:Sodium Channels; D052248:Nitric Oxide Synthase Type I; D002795:Choline O-Acetyltransferase