Symmetric synapses formed by callosal afferents in rat visual cortex.
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.
Hughes
C M
CM
Department of Anatomy and Neurobiology, Boston University School of Medicine, MA.
Peters
A
A
D000344:Afferent Pathways / Q000033:anatomy & histology* / Q000648:ultrastructure; D000818:Animals; D001369:Axons / Q000648:ultrastructure; D003337:Corpus Callosum / Q000033:anatomy & histology* / Q000648:ultrastructure; D003712:Dendrites / Q000648:ultrastructure; D008297:Male; D008854:Microscopy, Electron; D009410:Nerve Degeneration; D009474:Neurons / Q000166:cytology* / Q000648:ultrastructure; D011712:Pyramidal Tracts / Q000033:anatomy & histology* / Q000648:ultrastructure; D051381:Rats; D011919:Rats, Inbred Strains; D013569:Synapses / Q000648:ultrastructure*; D013788:Thalamus / Q000033:anatomy & histology / Q000648:ultrastructure; D014793:Visual Cortex / Q000033:anatomy & histology* / Q000648:ultrastructure