title: GABAergic synapses on mu-opioid receptor-expressing neurons in the superficial dorsal horn: an electron microscope study in the cat spinal cord.
abstract: 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.
authors.affiliation: Department of Anatomy and K.K. Leung Brain Research Centre, Fourth Military Medical University, Xi'an, PR China.
authors.forename: L W
authors.initials: LW
authors.lastname: Gong
authors.forename: Y Q
authors.initials: YQ
authors.lastname: Ding
authors.forename: D
authors.initials: D
authors.lastname: Wang
authors.forename: H X
authors.initials: HX
authors.lastname: Zheng
authors.forename: B Z
authors.initials: BZ
authors.lastname: Qin
authors.forename: J S
authors.initials: JS
authors.lastname: Li
authors.forename: T
authors.initials: T
authors.lastname: Kaneko
authors.forename: N
authors.initials: N
authors.lastname: Mizuno
mesh_terms: 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*
chemical_list: D017450:Receptors, Opioid, mu; D005680:gamma-Aminobutyric Acid