Fine structure of growth cones in the upper dorsal horn of the adult primate spinal cord in the course of reactive synapto-neogenesis.
Following transganglionic degenerative atrophy of primary afferent terminals induced by a crush-injury of the sciatic nerve, a regenerative process takes places in the upper dorsal horn of the lumbar spinal cord in the primate Macacus rhesus. Axonal growth cones are characterized by cisterns of axoplasmic reticulum; filopodia emanating from growth cones are electron-optically translucent sheet-like expansions, often containing growth-cone vesicles. Axoplasmic reticulum appears also in preterminal portions of regenerating axons. Dendritic growth cones contain a fine, filamentous matrix; electron-dense membrane specializations can be seen in well-defined areas of their surfaces. Immature synapses are formed between filopodia of axonal growth cones and dendritic growth cones. Electron-microscopic structures of this unique CNS regeneration are similar to those seen in the course of embryonic development of the spinal cord.
Knyihár-Csillik
E
E
Rakic
P
P
Csillik
B
B
D000818:Animals; D001370:Axonal Transport; D001369:Axons / Q000648:ultrastructure; D003712:Dendrites / Q000648:ultrastructure; D008251:Macaca; D008854:Microscopy, Electron; D009410:Nerve Degeneration; D009416:Nerve Regeneration; D013116:Spinal Cord / Q000502:physiology* / Q000648:ultrastructure; D013569:Synapses / Q000648:ultrastructure