Divergent levels of anxiety in mice selected for differences in sensitivity to a convulsant agent

Spontaneous behavior patterns were assessed in eight different behavioral situations in two lines of mice, BR and BS, previously selected for their sensitivity to an anxiogenic benzodiazepine (BZ) receptor inverse agonist, Methyl beta-carboline-3-carboxylate (beta-CCM). BR is highly resistant, and BS, highly sensitive to beta-CCM-induced seizures. Tests used included an assessment of general locomotor activity, several situations classically used for measuring fear-motivated behaviors (open field, thigmotaxis, elevated plus-maze, light-dark discrimination, staircase), a test for measuring exploration (holeboard), and a test for measuring nociception (hot-plate). In the absence of beta-CCM, the results provide evidence of reduced motor activity and higher levels of anxiety in the BR line as compared to the BS line.