title: GABAergic neurons in the ventrolateral subnucleus of the nucleus tractus solitarius are in contact with Kölliker-Fuse nucleus neurons projecting to the rostral ventral respiratory group and phrenic nucleus in the rat.
abstract: After ipsilateral injections of biotinylated dextran amine (BDA) into the ventrolateral subnucleus of the nucleus tractus solitarius (vlNTS) and Fluoro-gold (FG) into the rostral ventral respiratory group (rVRG) region or into the phrenic nucleus (PhN) region in the rat, an overlapping distribution of BDA-labeled axon terminals and FG-labeled neurons was found in the Kölliker-Fuse (KF) nucleus ipsilateral to the injection sites. Using retrograde tracing combined with immunohistochemistry for glutamic acid decarboxylase isoform 67 (GAD67), we indicated that as many as 40% of the vlNTS neurons projecting to the KF were immunoreactive for GAD67. Using a combination of anterograde and retrograde tracing techniques, and immunohistochemistry for GAD67, we further demonstrated that the vlNTS axon terminals with GAD67 immunoreactivity established close contact to the rVRG- or PhN-projecting KF neurons. The present results suggest that GABAergic vlNTS fibers may exert inhibitory influences on the rVRG- as well as PhN-projecting KF neurons and these circuits may be involved in the respiratory reflexes such as the Hering-Breuer reflex.
authors.affiliation: Department of Anatomy and Morphological Neuroscience, Shimane University School of Medicine, Izumo 693-8501, Japan.
authors.forename: Shigefumi
authors.initials: S
authors.lastname: Yokota
authors.forename: Toshiko
authors.initials: T
authors.lastname: Tsumori
authors.forename: Tatsuro
authors.initials: T
authors.lastname: Oka
authors.forename: Sawako
authors.initials: S
authors.lastname: Nakamura
authors.forename: Yukihiko
authors.initials: Y
authors.lastname: Yasui
mesh_terms: D000818:Animals; D001370:Axonal Transport / Q000502:physiology; D001710:Biotin / Q000031:analogs & derivatives / Q000737:chemistry; D002352:Carrier Proteins / Q000378:metabolism; D003911:Dextrans / Q000737:chemistry; D005456:Fluorescent Dyes / Q000737:chemistry; D005968:Glutamate Decarboxylase / Q000378:metabolism; D007150:Immunohistochemistry; D008297:Male; D018613:Microscopy, Confocal; D009434:Neural Pathways / Q000502:physiology*; D009474:Neurons / Q000166:cytology / Q000378:metabolism* / Q000502:physiology; D010791:Phrenic Nerve / Q000502:physiology; D017729:Presynaptic Terminals / Q000378:metabolism / Q000502:physiology; D051381:Rats; D017208:Rats, Wistar; D012125:Respiratory Center / Q000166:cytology / Q000378:metabolism* / Q000502:physiology; D017552:Solitary Nucleus / Q000166:cytology / Q000378:metabolism* / Q000502:physiology; D013266:Stilbamidines / Q000737:chemistry; D009435:Synaptic Transmission / Q000502:physiology; D005680:gamma-Aminobutyric Acid / Q000378:metabolism
chemical_list: C049774:2-hydroxy-4,4'-diamidinostilbene, methanesulfonate salt; D002352:Carrier Proteins; D003911:Dextrans; D005456:Fluorescent Dyes; D013266:Stilbamidines; C076397:biotinylated dextran amine; D005680:gamma-Aminobutyric Acid; D001710:Biotin; D005968:Glutamate Decarboxylase; C402565:glutamate decarboxylase 1