Table 2.

Axonal degeneration in β1 (−/−) optic nerves

Animal	Number of degenerating axons per cross-section of optic nerve
β1 (+/+) 1102-1	52
β1 (+/+) 3122-1	34
β1 (+/+) 3196	22
Mean ± SEM	36 ± 8.7
β1 (−/−) 1102-1	85
β1 (−/−) 3121-1	107
β1 (−/−) 3148	52
Mean ± SEM	81 ± 16; p = 0.067

Ultrathin optic nerve cross-sections were prepared from β1 (+/+) and β1 (−/−) mice and analyzed as described in Materials and Methods. Degenerating axons were defined as collapsed or delaminated myelinated axons containing membranous debris. Entire cross-sectional areas were examined at 3400X. Degenerated axons were counted and reported as mean ± SEM. p value was determined using Student's t test (SigmaPlot).