RUI: The Vestibulo-Ocular System in Lungfish

University Of Houston - Clear Lake, Houston TX

Investigators

Abstract

The vestibulo-ocular reflex (VOR) is a behavior that stabilizes visual images on the retina during head movements. It has been demonstrated that Cartilaginous fishes have an eye muscle innervation pattern and VOR circuitry that is different from most vertebrates. The lungfish are more closely related to tetrapods than to other vertebrates, but they are believed to have an eye muscle innervation pattern similar to that of Cartilaginous fishes. It is therefore hypothesized that lungfish have a VOR circuitry like that of Cartilaginous fishes. Testing this hypothesis requires that the organization of the oculomotor nuclei and VOR circuitry be determined in a representative of the lungfish. The African lungfish is chosen based on its commercial availability. Two sets of experiments are proposed. In the first set of experiments, retrograde transport of biotinylated dextrans amines (BDA) will be used to reveal the organization of the oculomotor nucleus. In the second set, injections of BDA into the oculomotor nucleus will be used to reveal the organization of the VOR connections. This research will contribute to our understanding of the evolution of eye movement control systems in the vertebrate brain. Additionally, the research project will provide experiences for undergraduates in basic neuroscience research.