Figure 1.

Predator exposure test apparatus. The mouse was transferred to the testing apparatus and allowed to explore the corridor and stimulus chamber first in the absence of the rat, then in the presence of the rat, and lastly without the rat. A, Representative example of mouse position during pre-rat (left), rat (middle), and post-rat (right) phases. B, Example of a representative center of mass mouse body tracking during the pre-rat (left), rat (middle), and post-rat (right) phases. C, Heat-map showing average cumulative time in the apparatus in the pre-rat (left), rat (middle), and post-rat (right) phases (N = 12). D, Sequence of video frames for a representative mouse executing approach and flight during the rat exposure phase: approach (assessment) and flight (retraction, turning, running, arriving).