Symmetric synapses formed by callosal afferents in rat visual cortex

Brain Res. 1992 Jun 26;583(1-2):271-8. doi: 10.1016/s0006-8993(10)80033-2.

Abstract

Following an electron microscopic examination of 437 degenerating terminals of callosally projecting axons in layer II/III at the 17/18a border, it has been found that some of these terminals form symmetric synapses with dendritic shafts (1.83%), pyramidal cell bodies (1.37%) and dendritic spines (0.46%). The remainder of the axon terminals (96.33%) form asymmetric synapses, mainly with dendritic spines although a few form synapses with dendrites. These results suggest that in the rat visual cortex the corpus callosum is a source of both inhibitory and excitatory input to the contralateral hemisphere.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Afferent Pathways / anatomy & histology*
  • Afferent Pathways / ultrastructure
  • Animals
  • Axons / ultrastructure
  • Corpus Callosum / anatomy & histology*
  • Corpus Callosum / ultrastructure
  • Dendrites / ultrastructure
  • Male
  • Microscopy, Electron
  • Nerve Degeneration
  • Neurons / cytology*
  • Neurons / ultrastructure
  • Pyramidal Tracts / anatomy & histology*
  • Pyramidal Tracts / ultrastructure
  • Rats
  • Rats, Inbred Strains
  • Synapses / ultrastructure*
  • Thalamus / anatomy & histology
  • Thalamus / ultrastructure
  • Visual Cortex / anatomy & histology*
  • Visual Cortex / ultrastructure