Morphological evidence for GABA/glycine-cocontaining terminals in synaptic contact with neurokinin-1 receptor-expressing neurons in the sacral dorsal commissural nucleus of the rat.
Previous studies have shown that neurons in the sacral dorsal commissural nucleus (SDCN) express neurokinin-1 receptor (NK1R) and can be modulated by the co-release of GABA and glycine (Gly) from single presynaptic terminal. These results raise the possibility that GABA/Gly-cocontaining terminals might make synaptic contacts with NK1R-expressing neurons in the SDCN. In order to provide morphological evidence for this hypothesis, the triple-immunohistochemical studies were performed in the SDCN. Triple-immunofluorescence histochemical study showed that some axon terminals in close association with NK1R-immunopositive (NK1R-ip) neurons in the SDCN were immunopositive for both glutamic acid decarboxylase (GAD) and glycine transporter 2 (GlyT2). In electron microscopic dual- and triple-immunohistochemistry for GAD/GlyT2, GAD/NK1R, GlyT2/NK1R, or GAD/GlyT2/NK1R also revealed dually labeled (GAD/GlyT2-ip) synaptic terminals upon SDCN neurons, as well as GAD- and/or GlyT2-ip axon terminals in synaptic contact with NK1R-ip SDCN neurons. These results suggested that some synaptic terminals upon NK1R-expressing SDCN neurons co-released both GABA and Gly.
Feng
Yu-Peng
YP
Department of Anatomy and K. K. Leung Brain Research Centre, The Fourth Military Medical University, Xi'an 710032, PR China.
Li
Yun-Qing
YQ
Wang
Wen
W
Wu
Sheng-Xi
SX
Chen
Tao
T
Shigemoto
Ryuichi
R
Mizuno
Noboru
N
D000818:Animals; D005455:Fluorescent Antibody Technique; D005968:Glutamate Decarboxylase / Q000378:metabolism; D005998:Glycine / Q000378:metabolism*; D008297:Male; D046529:Microscopy, Electron, Transmission; D009475:Neurons, Afferent / Q000378:metabolism / Q000648:ultrastructure; D009619:Nociceptors / Q000378:metabolism / Q000648:ultrastructure; D010146:Pain / Q000378:metabolism / Q000503:physiopathology; D017729:Presynaptic Terminals / Q000378:metabolism* / Q000648:ultrastructure; D051381:Rats; D017208:Rats, Wistar; D018040:Receptors, Neurokinin-1 / Q000378:metabolism*; D012447:Sacrum; D013116:Spinal Cord / Q000378:metabolism* / Q000648:ultrastructure; D013373:Substance P / Q000378:metabolism; D013570:Synaptic Membranes / Q000378:metabolism / Q000648:ultrastructure; D009435:Synaptic Transmission / Q000502:physiology; D017833:Visceral Afferents / Q000378:metabolism* / Q000648:ultrastructure; D005680:gamma-Aminobutyric Acid / Q000378:metabolism*
D018040:Receptors, Neurokinin-1; D013373:Substance P; D005680:gamma-Aminobutyric Acid; D005968:Glutamate Decarboxylase; D005998:Glycine