Lesion-induced CA1 mossy fibers in the rat represent a neoinnervation.
The developmental pattern of hippocampal mossy fiber (dentate granule cell axon) innervation to the pyramidal cell layer was examined with anterograde transport methods. Injection of 3H-leucine into the dentate gyrus on PN 1 resulted in labeling of the incipient stratum lucidum extending to, but not beyond, the CA3 region on PN 3 and 5. Since destruction of CA3 pyramidal cells on PN 5 results in aberrant mossy fiber innervation to CA1 pyramidal cells (Cook and Crutcher 1985), these results suggest that the presence of mossy fibers in CA1 of the rat represents a neoinnervation (perhaps representing a more primitive pattern of connectivity) and not the persistence of a transient developmental projection.
Cook
T M
TM
Department of Anatomy, University of Utah School of Medicine, Salt Lake City 84132.
Crutcher
K A
KA
D000818:Animals; D000831:Animals, Newborn; D001345:Autoradiography; D006624:Hippocampus / Q000166:cytology / Q000254:growth & development*; D006735:Horseradish Peroxidase; D007930:Leucine; D051381:Rats; D018998:Wheat Germ Agglutinin-Horseradish Peroxidase Conjugate; D014909:Wheat Germ Agglutinins
D018998:Wheat Germ Agglutinin-Horseradish Peroxidase Conjugate; D014909:Wheat Germ Agglutinins; D006735:Horseradish Peroxidase; D007930:Leucine