Fig. 7. Measures of spatial memory performance of frizzled 9 mutant mice [+/+ (n=8), +/– (n=12), –/– (n=9)] tested in the Morris water maze (Morris, 1984) under the place/spatial testing condition. Presented are Probe Times in seconds (A) and Number of Annulus Crossings (B) measured during probe trials (i.e. memory trials). The frizzled 9 mutant (–/–) mice displayed significantly (^*P<0.04) poorer spatial memory performance on both measures than the +/+ mice, and the +/– mice tended to be intermediate.