Fig. 1: Neuropathological and neurobehavioral features of D-alanine-fed DAAO-TGCdh5 mice.
a shows a pictorial representation of a transverse section through the mouse spinal cord noting the dorsal column. b, c show representative haematoxylin/eosin staining of a transverse section of the lumbar spinal cord isolated from control (b), n = 3 biologically independent Cre+/TG− mice and DAAO-TGCdh5 (c) mice that had been treated for 6 days with D-alanine, revealing marked and highly selective degeneration of the dorsal column (noted by the arrows) only in the transgenic mouse, n = 3 biologically independent mice. Scale bars indicate 100 μm. d shows a pictorial representation of the open field mouse behavioral test60, in which mice are allowed to move freely for a fixed amount of time while their activity is quantitated by infrared beams mounted in the apparatus. e shows quantitation of field activity traces for a representative DAAO-TGCdh5 mouse and a Cre+/TG− control mouse before and after providing D-alanine (D-Ala) in their drinking water for 4 days, as noted; f presents the results of summary data for this behavioral assay obtained for n = 7 DAAO-TGCdh5 mice and n = 6 control mice. Data are presented as mean values ± SEM; ***denotes p < 0.001 (by two-way ANOVA); g presents a pictorial representation of the Rotarod test60, in which mice are placed on a slowly rotating rod and the time until they fall off the rod (latency to fall) is monitored as an index of balance and coordination. Both DAAO-TGCdh5 mice and littermate control Cre+/TG− mice were treated with D-alanine in the drinking water and tested daily; a pictorial representation of the apparatus is shown below, and summary results are shown above. Data are presented as mean values ± SEM; ***denotes p < 0.001 (by two-way ANOVA); n = 7 DAAO-TGCdh5 and n = 6 Cre+/TG− control mice each group. h shows the results of grip strength testing61 of DAAO-TGCdh5 and littermate Cre+/TG− control mice treated with D-alanine; a pictorial representation of the testing apparatus is shown below. Data are presented as mean values ± SEM; ***denotes p < 0.001 (two-way ANOVA) and n = 7 DAAO-TGCdh5 and n = 6 Cre+/TG− mice were studied in each group.
