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Specification of retinal central connections in Rana pipiens before the appearance of the first post‐mitotic ganglion cells
Author(s) -
Sharma S. C.,
Hollyfield Joe G.
Publication year - 1974
Publication title -
journal of comparative neurology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.855
H-Index - 209
eISSN - 1096-9861
pISSN - 0021-9967
DOI - 10.1002/cne.901550403
Subject(s) - biology , tectum , retina , ganglion , anatomy , giant retinal ganglion cells , parasol cell , retinal , fundus (uterus) , intrinsically photosensitive retinal ganglion cells , optic nerve , embryonic stem cell , neuroscience , mitosis , retinal ganglion cell , microbiology and biotechnology , central nervous system , midbrain , ophthalmology , genetics , medicine , biochemistry , gene
The order of production of retinal cells and the time when retinal cells become post‐mitotic was studied in Rana pipiens embryos using 3 H‐thymidine autoradiography. Cell division stops first in the fundus of the retinal rudiment between embryonic stages 17 and 18 and gradually becomes restricted to the retinal margin. The ganglion cells in the fundus are among the first cells to become post‐mitotic. The specification of the central connections of ganglion cells was studied by rotating the eye primordium at embryonic stages 16–21. After metamorphosis, the visual projection from the rotated eye to the contralateral optic tectum was mapped electrophysiologically and compared with the normal retinotectal map. In all cases, the visual projection map was rotated through the same angle as was indicated by the position of the choroidal fissure. It appears that ganglion cell connections with the tectum were specified by stage 17. These results indicate that ganglion cell central connections are specified before the first ganglion cells become post‐mitotic.