At the optic chiasm the two optic nerves fuse, and fibers from each eye cross the midline or turn back and remain uncrossed. Having adopted their pathways the fibers separate to form the two optic tracts. Research into the architecture and development of the chiasm has become an area of increasing interest. Many of its mature features are complex and vary between different animal types. It is p...

During normal development, retinal ganglion cells (RGCs) project axons along the optic nerve to the optic chiasm on the ventral surface of the hypothalamus. In rodents, most RGC growth cones then cross the ventral midline to join the contralateral optic tract; those that do not cross join the ipsilateral optic tract. Contralaterally projecting RGCs are distributed across the retina whereas ipsi...

During mammalian development, retinal ganglion cell (RGC) axons from nasal retina cross the optic chiasm midline, whereas temporal retina axons do not and grow ipsilaterally, resulting in a projection of part of the visual world onto one side of the brain while the remaining part is represented on the opposite side. Previous studies have shown that RGC axons in GAP-43-deficient mice initially f...

Right-sided blindness developed in a patient after three intraarterial treatments with cis-platinum for a right temporal glioblastoma multiforme. MR showed an enlarged and enhancing optic chiasm. Because of the history of remote radiation therapy and the fact that the tumor was located distal to the optic chiasm, we postulate that the clinical and imaging findings were related to the chemotoxic...

The optic chiasm is an important midline choice point where retinal ganglion cell (RGC) axons from each eye diverge to targets on both sides of the brain, setting up binocular vision. While several cues essential for guidance at the optic chiasm have been identified, it is clear other signals are required. We have begun to investigate the role of the highly related homophilic cell adhesion mole...

Axons receive guidance information from extrinsic cues in their environment in order to reach their targets. In the frog Xenopus laevis, retinal ganglion cell (RGC) axons make three key guidance decisions en route through the brain. First, they cross to the contralateral side of the brain at the optic chiasm. Second, they turn caudally in the mid-diencephalon. Finally, they must recognize the o...

In animals with binocular vision, retinal ganglion cell (RGC) axons from each eye sort in the developing ventral diencephalon to project to ipsi- or contralateral targets, thereby forming the optic chiasm. Ipsilaterally projecting axons arise from the ventrotemporal (VT) retina and contralaterally projecting axons primarily from the other retinal quadrants. The winged helix transcription factor...

GAP-43 is an abundant intracellular growth cone protein that can serve as a PKC substrate and regulate calmodulin availability. In mice with targeted disruption of the GAP-43 gene, retinal ganglion cell (RGC) axons fail to progress normally from the optic chiasm into the optic tracts. The underlying cause is unknown but, in principle, can result from either the disruption of guidance mechanisms...

The optic chiasm is an important midline choice point where retinal ganglion cell (RGC) axons from each eye diverge to targets on both sides of the brain, setting up binocular vision. While several cues essential for guidance at the optic chiasm have been identified, it is clear other signals are required. We have begun to investigate the role of the highly related homophilic cell adhesion mole...