Introduction to Tectal Lobe Lesions and
Predictions about their Effect on Behavior

I have focused my research on looking at the role that the optic tectum plays in the frog nervous system. The optic tectum is a structure in the brain that the retina maps onto topographically via the optic nerve. For a given point on the retina there is an equivalent point on the contralateral(meaning opposite side of the body) tectal lobe. Frogs can see 360 degrees around them at all times, with each eye's range extending 45 degrees across the mid-saggital plane(the frog's mid-line) in front and about 15 degrees behind, so for a given stimulus in the binocluar field the tectum can be activated on both sides. The specific question that I am currently addressing is whether or not the removal of a tectal lobe has any effect on the behavior of a frog that already has a contralateral optic nerve lesion.

Our prediction based on the current model of the frog nervous system says that we should see no change in behavior when the tectal lobe is removed after an optic nerve lesion. The original optic nerve lesion should produce no effect on behavior itslef, other than creating a deficit field in the ipsilateral(same side of the body ) monocular field. The tectal lobe lesions are predicted to create the same effects as were predicted for the optic nerve lesions, which is no effect on behavior other than the deficit field. This seems to make sense because by removing the tectal lobe the frog does not recieve any information from the contralateral retina, which is the same thing as lesioning the optic nerve leading to that tectal lobe. Thus the combination of the two procedures should produce no effect on behavior since the deficit fields are the same.

Data Interpretation

|| Introduction | Data Interpretation | Conclusion | Home Page ||

This page was last updated on August 7th, 1998
and is maintained by Zach Hettinger.