Some of this neural circuitry involves the limbic system. Animals and humans with hippocampal damage are impaired on a variety of visual memory, spatial and navigational tasks. Previous studies have shown that two types of spatial cells in the limbic system code exocentric spatial information. Panel A above shows a typical response of a head direction cell in the rat hippocampus. Rotating visual landmarks around the animal shifts the preferred direction by a corresponding amount.
Response is independent of pitch and roll of the animal's head.
We are quantifying the three dimensional response characteristics of rats which have been trained to crawl walls, floor and ceiling of special test chambers, such as the one shown in Panel B . Our goal is to see whether and how directional tuning is maintained during both the weightless and hypergravic phases of flight. Shape from shading in different frames of reference. The contribution of motion, the visual frame, and visual polarity to sensations of body tilt.