GABA immunoreactive axons and growth cones in the developing chicken optic nerve and tract.
Immunohistochemical studies of the chicken embryo optic tract using an antibody to gamma-aminobutyric acid (GABA) reveal that the tract is initially free of GABA immunoreactive axons. During the second week of incubation, GABA+ axons appear in the tract, chiasm, and optic nerve. The number of GABA+ axons in the optic nerve increases through E18, although few are recognizable after hatching. Detailed staining of GABA+ growth cones confirmed that virtually all the GABA+ axons in the optic nerve were growing toward the retina. Taken together, the findings suggest that the GABA+ axons in the chiasm and nerve are largely a transient extension of the GABA+ optic tract cells, the tectogeniculate projection, or both.
Granda
R H
RH
Department of Anatomy and Cell Biology, Wayne State University, School of Medicine, Detroit, MI 48201.
Crossland
W J
WJ
D000818:Animals; D002642:Chick Embryo; D007150:Immunohistochemistry; D009474:Neurons / Q000378:metabolism; D009900:Optic Nerve / Q000166:cytology / Q000196:embryology / Q000378:metabolism*; D014795:Visual Pathways / Q000166:cytology / Q000196:embryology / Q000378:metabolism*; D005680:gamma-Aminobutyric Acid / Q000378:metabolism*
D005680:gamma-Aminobutyric Acid