Behavioral assessment of visual acuity in mice and rats

We have developed a simple computer-based discrimination task that enables the quick determination of visual acuities in rodents. A grating is display ed randomly on one of two monitors at the wide end of a trapezoidal-shaped tank containing shallow water. Animals are trained to swim toward the scree ns, and at a fixed distance, choose the screen displaying the grating and e scape to a submerged platform hidden below it. Both mice and rats learn the task quickly. Performance falls below 70% when the spatial frequency is in creased beyond 0.5 cycles in most C57BU6 mice, and around 1.0 cycles per de gree (cpd) in Long-Evans rats. (C) 2000 Elsevier Science Ltd. Ail rights re served.