Table 1.

Quantification of Dilated Axons in Brain and Spinal Cord of Transgenic Mice

Mouse type	n	Spinal cord	Cerebral cortex
		Mean no.*	Mean no. rostral**	Mean no. caudal***
WT	4	0	0	0
1H	5	9.3	9.1	3.7
1HH	3	22.0	29.9	11.5
5HH	3	4.3	5.6	2.7

Numbers of dilated axons in entire transversal sections of the spinal cord (6 μm thick) and in coronal sections of the entire right hemispheric cortex (40 μm thick) are presented. Numbers of dilated axons in the rostral and caudal part of the cerebral neocortex from sections through the hippocampus were counted. Silver impregnation (nine sections per mouse type counted) and SMI-32 immunostaining (eight sections per mouse type counted) yielded similar results. Mice used were 3 months of age.

The Kruskal-Wallis analysis revealed a gene-dosage related pathology in the spinal cord and hemispheric cortex. *1H-5HH: P = 0.02; 1HH-5HH: P = 0.049; 1HH-1H: P = 0.02. **1H-5HH: P = 0.025; 1HH-5HH: P = 0.049; 1HH-1H: P = 0.025. ***1H-5HH: P = 0.23; 1HH-5HH: P = 0.049; 1HH-1H: P = 0.025.

WT, wild-type mice; 1H and 1HH, heterozygous and homozygous htau40-1 mice, respectively; 5HH, homozygous htau40-5 mice; n, number of mice analyzed.