gamma-aminobutyric acid- and glycine-immunoreactive neurons postsynaptic to substance P-immunoreactive axon terminals in the superficial layers of the rat medullary dorsal horn.
gamma-Aminobutyric acid (GABA)ergic and glycinergic neurons were examined light- and electron-microscopically in laminae I and II of the medullary dorsal horn (MDH, i.e. spinal trigeminal nucleus caudalis in the rat). The majority of GABA- and glycine (Gly)-immunoreactive (-ir) neurons showed both GABA- and Gly-immunoreactivities (-IRs). Noxious stimulation (subcutaneous injection of formalin into perioral regions) induced Fos-IR in some of GABA- and Gly-ir neurons. GABA- and Gly-ir neuronal profiles were postsynaptic to substance P-ir axon terminals. These results suggest that nociceptive information being carried by primary afferent SP-fibers may be relayed directly to GABAergic and glycinergic neurons in laminae I and II of the MDH.
Wang
D
D
Department of Anatomy and K.K. Leung Brain Research Centre, The Fourth Military Medical University, 710032, PR, Xi'an, China.
Li
Y Q
YQ
Li
J L
JL
Kaneko
T
T
Nomura
S
S
Mizuno
N
N
D000818:Animals; D019706:Excitatory Postsynaptic Potentials / Q000502:physiology; D019085:Fluorescent Antibody Technique, Direct; D005998:Glycine / Q000032:analysis*; D007150:Immunohistochemistry; D008297:Male; D008526:Medulla Oblongata / Q000737:chemistry / Q000648:ultrastructure; D008854:Microscopy, Electron; D020671:Posterior Horn Cells / Q000737:chemistry* / Q000648:ultrastructure; D017729:Presynaptic Terminals / Q000737:chemistry*; D051381:Rats; D017208:Rats, Wistar; D013373:Substance P / Q000032:analysis*; D014275:Trigeminal Caudal Nucleus / Q000737:chemistry* / Q000648:ultrastructure; D005680:gamma-Aminobutyric Acid / Q000032:analysis*
D013373:Substance P; D005680:gamma-Aminobutyric Acid; D005998:Glycine