ISSN:
0003-276X
Keywords:
Life and Medical Sciences
;
Cell & Developmental Biology
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Medicine
Notes:
Factors contributing to the retino-tectal course of the optic nerves in cyclopic and synophthalmic zebrafish embryos were evaluated. The eye abnormalities were produced by immersing blastula stage eggs in 3% ethanol for two hours. Approximately 50% of cyclopic eyes produced one optic nerve that exits from the eye to innervate one optic tectum. The remaining half of the cyclopic embryos formed optic nerves that were unable to exit from the eyes.In the synophthalmic embryos, two optic nerves were always produced. These nerves either joined within the partially fused retinas, or shortly after exit from the eyes, to form one nerve which entered the brain and innervated only one optic tectum. Crossing over was not seen within the fused eyes or after exit from the eyes.The resultant single optic nerves in the cyclopic and synophthalmic embryos innervated the side of the brain penetrated by the nerve. They entered in the floor of the forebrain, diencephalon, or midbrain, usually asymmetrically. Axial growth, directional orientation, and contact guidance of matrix configurations appeared an adequate explanation for the establishment of the retino-tectal pathway.
Additional Material:
1 Tab.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/ar.1091800211
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