title: L-aspartate-immunoreactive neurons in the rat enteric nervous system.
abstract: L-aspartate (L-Asp) is an excitatory neurotransmitter in the central nervous system. In the present study, we demonstrate, for the first time, the presence of L-Asp in a particular neuronal cell class in the enteric nervous system (ENS). Scattered L-Asp-immunoreactive neuronal cell bodies and nerve fibers were found extensively in both the myenteric and submucosal plexus throughout the small and large intestines. Many L-Asp-immunoreactive nerve fibers, which originated from intrinsic nerve cell bodies, were found in the ganglia and interconnecting nerve bundles. Electron microscopy revealed that L-Asp-immunoreactive terminals frequently formed synaptic contacts with intrinsic nerve cells, suggesting that some L-Asp-immunoreactive neurons might function as interneurons. These results suggest that L-Asp-immunoreactive neurons play a significant role within the ENS to control intestinal functions. The presence of enteric L-Asp-immunoreactive neurons provides strong support for the proposal that L-Asp is a neuromodulator in the rat ENS.
authors.affiliation: Department of Anatomy II, Mie University School of Medicine, 2-174 Edobashi, 514-0001, Tsu, Mie, Japan. nagahama@doc.medic.mie-u.ac.jp
authors.forename: Masato
authors.initials: M
authors.lastname: Nagahama
authors.forename: Ning
authors.initials: N
authors.lastname: Ma
authors.forename: Reiji
authors.initials: R
authors.lastname: Semba
mesh_terms: D000818:Animals; D001224:Aspartic Acid / Q000378:metabolism*; D017615:Enteric Nervous System / Q000502:physiology*; D007124:Immunoenzyme Techniques; D007420:Intestine, Large / Q000294:innervation*; D007421:Intestine, Small / Q000294:innervation*; D008297:Male; D046529:Microscopy, Electron, Transmission; D009197:Myenteric Plexus / Q000166:cytology* / Q000378:metabolism; D009412:Nerve Fibers / Q000378:metabolism / Q000648:ultrastructure; D009474:Neurons / Q000166:cytology / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar; D013368:Submucous Plexus / Q000166:cytology* / Q000378:metabolism; D013569:Synapses / Q000648:ultrastructure
chemical_list: D001224:Aspartic Acid