GABAergic synapses on mu-opioid receptor-expressing neurons in the superficial dorsal horn: an electron microscope study in the cat spinal cord.
A double-immunocytochemical electron microscope study was performed in the cat to examine whether GABAergic axons might be in synaptic contact with spinal neurons expressing mu-opioid receptor (MOR) in laminae I and II of the spinal dorsal horn at the lumbar cord segments. Structures showing MOR-like immunoreactivity (-LI) and those showing GABA-LI were labeled, respectively, with diaminobenzidine/peroxidase-reaction products and immunogold particles. Approximately one-third of dendritic profiles with MOR-LI in laminae I and II were postsynaptic to axon terminals with GABA-LI; about one-fourth of somatic profiles with MOR-LI were also postsynaptic to axon terminals with GABA-LI. The results suggest that activation of MOR on postsynaptic neurons may modulate effects which are induced by GABA released from presynaptic neurons.
Gong
L W
LW
Department of Anatomy and K.K. Leung Brain Research Centre, Fourth Military Medical University, Xi'an, PR China.
Ding
Y Q
YQ
Wang
D
D
Zheng
H X
HX
Qin
B Z
BZ
Li
J S
JS
Kaneko
T
T
Mizuno
N
N
D000818:Animals; D002415:Cats; D008161:Lumbosacral Region; D016253:Microscopy, Immunoelectron; D009474:Neurons / Q000737:chemistry*; D017450:Receptors, Opioid, mu / Q000032:analysis*; D013116:Spinal Cord / Q000737:chemistry* / Q000166:cytology; D013569:Synapses / Q000502:physiology*; D005680:gamma-Aminobutyric Acid / Q000502:physiology*
D017450:Receptors, Opioid, mu; D005680:gamma-Aminobutyric Acid