Directional consistency: Determinant of learned maze performance of five mice strains

The heterogeneous mouse stocks HS/lbg and SABRA/HUC, and the inbred strains C57B1/6J, CBA/LAC, and BALB/crgl (a total of 88 mice), were employed in an investigation on strain differences in delayed spontaneous alternations (SA), and eight-arm-maze performance (EAM). Intact male mice were tested for SA at age 41 days for two consecutive days, and for EAM at age 50-54 days, under conditions of water deprivation that commenced on day 43. The concept of EAM directional consistency (DC), proposed and defined here, was found highly related to EAM performance, and a better predictor of SA than EAM performance. Faceted smallest space analysis (FSSA), which provides a broad, simultaneous, perspective on the various maze behaviors observed (SA, EAM, DC), indicates that DC is both more closely related to SA and a more coherent concept than performance. The findings suggest that DC is a more elementary behavior, possibly related to different etiology than that of performance. Whilst in some studies EAM performance is viewed as spatial, here DC of mice suggest that, in fact, the animals are learning a set of rules. The results confirmed the superiority of the outbred HS over the inbred CBA, C57 and BALB, with SABRA occupying an intermediate position, and indicate that the medium performance strains rely on DC more than the others.