Anxiety in the elevated zero-maze is augmented in mice after repeated daily exposure.

We recently tested three inbred mouse strains (C57BL/6J, DBA/2J, C3H/HeJ) and two F1 hybrids (B6C3F1/J, C3D2F1/J) in an elevated zero-maze for 3 consecutive days. As measured by the latency to enter an open quadrant and percentage of time spent in the open, anxiety increased over the three trials. Furthermore, we observed that some strains used visual cues to avoid the open arms of the zero-maze on the initial exposure, while other strains may have used other sensory cues. These results suggest that strains differentially use or retain information, gathered from the initial exposure, to avoid the open quadrants on subsequent exposure to the maze. Moreover, this repeated trial test may more accurately reflect anxiety in strains that are visually impaired.