Rats in Space

Insiders dubbed it the "vomit comet" for the queasy, carnival-ride sensation it evokes. But the KC-135 aircraft which flies a series of highspeed parabolic trajectories resulting in 20-second windows of weightlessness has been used to answer some serious scientific questions. Associate professor of psychology Jeffrey Taube, who studies e neurobiology of spatial cognition (how we sense location and direction) will board the aircraft this summer, along with post-doctoral fellow Robert Stackman and a few laboratory rats, to gain a better understanding of the role that visual cues and gravity receptors in the inner ear play in how animals orient themselves.

"The question we're exploring is important for space travel, since zero-gravity changes the meaning of 'down,'" says Taube. "A phenomenon familiar to astronauts is the visual reorientation illusion, or VRI. Someone will be at work, standing on the floor of the spacecraft, when suddenly they see someone else standing on the ceiling. The result is the immediate feeling of being upside down, which brings on a wobbly queasiness similar to the feeling you have when you get off an amusement park ride." The neurobiology of the VRI response is related to the way the animal brain constructs a mental map of where-I-am and what-direction-I'm-facing, essential information for orientation and navigation. Taube's lab has found that both vision and the hair cells in the inner ear play a key role in tracking these coordinates when an animal navigates and then "retunes" its cognitive coordinates in a new setting. The KC-135 experiments are designed to see what the rats' head-direction cells do in the absence of gravity.

Jeffrey Taube (left) and RobertStackman wonder if rats will findweightlessness disorienting.