Anxiety-related behaviors in the elevated zero-maze are affected by genetic factors and retinal degeneration

Anxiety levels were tested in an elevated zero-maze for 8 inbred strains of mice that are used widely in biomedical and behavioral research. Strain differences were observed for activity, latency to enter an open quadrant, open time, and defecation, demonstrating that genetic factors mediate anxiety in this paradigm. Three of the strains have the rdl mutation that causes retinal degeneration and were less anxious in the maze. To discern whether visual acuity is a source of difference on the maze, anxiety levels were tested in a congenic strain in which the rdl allele has been replaced with the wild-type allele. The, congenic strain, with normal vision. had higher levels of anxiety. This study provides baseline data for the selection and use of any of these strains in pharmacological challenges in the maze. and provides a starting point for the identification of strains that may have appropriate backgrounds for targeted mutation studies.