Genetic influences on latent inhibition.

The present study examined the development of latent inhibition in a number of inbred strains of mice. C57BL/6J, DBA/2J, C3H/Ibg, BALB/cByJ, A/J, CBA/J, 129/SvevTac, 129/SvJ, and AKR/J mice were screened for the development of latent inhibition. The latent inhibition paradigm involved 1 day of either 40 preexposures to the conditioned stimulus (CS) or no preexposure. On the following training day, the CS was twice paired with a shock unconditioned stimulus (US). On a subsequent test day, the strength of the CS-US association was measured. Mice preexposed to the CS should show a weaker CS-US association, which would reflect development of latent inhibition. Significant between-strain differences existed. The 129/Svev, C57BL/6, BALB/cByJ, AKR, and DBA/2 mice developed latent inhibition, but 129/SvJ, CBA, A, and C3H mice did not. Thus, genetic variance contributes to variability in the development of latent inhibition.