title: Ultrastructural evidence for GABA-mediated disinhibitory circuits in the spinal cord of the cat.
abstract: The synaptic relationships between gamma-aminobutyric acid (GABA)-immunoreactive and enkephalin-immunoreactive profiles in the cat spinal cord were examined using combined pre-embedding immunoperoxidase and post-embedding immunogold electron microscopic immunocytochemistry. Although colchicine was not used, enkephalin-immunoreactive somata and dendrites were detected in regions associated with nociceptive transmission, including laminae I, II, V and X. In each of these laminae, many GABA-immunoreactive terminals were found presynaptic to enkephalin-immunoreactive cell bodies and dendrites. We propose that disinhibition of opioid-containing neurons may be a common feature of pain-related circuits in the cat spinal cord.
authors.affiliation: Department of Anatomy, University of California, San Francisco 94143.
authors.forename: H
authors.initials: H
authors.lastname: Liu
authors.forename: I J
authors.initials: IJ
authors.lastname: Llewellyn-Smith
authors.forename: P
authors.initials: P
authors.lastname: Pilowsky
authors.forename: A I
authors.initials: AI
authors.lastname: Basbaum
mesh_terms: D000818:Animals; D002415:Cats; D003712:Dendrites / Q000502:physiology / Q000648:ultrastructure; D004745:Enkephalins / Q000032:analysis; D007124:Immunoenzyme Techniques; D016253:Microscopy, Immunoelectron; D009474:Neurons / Q000502:physiology* / Q000648:ultrastructure; D013116:Spinal Cord / Q000502:physiology* / Q000648:ultrastructure; D013569:Synapses / Q000502:physiology* / Q000648:ultrastructure; D005680:gamma-Aminobutyric Acid / Q000032:analysis / Q000502:physiology*
chemical_list: D004745:Enkephalins; D005680:gamma-Aminobutyric Acid