Ultrastructure | ||||||
---|---|---|---|---|---|---|
Genotype | AChR cluster area (μm2) | Number of axons per muscle fiber | Nerve terminal cross-sectional area (μm2) | Number of active zones per nerve terminal profile | Vesicle number within 20 nm of active zone | Vesicle number within 50 nm of active zone |
+/+ | 47 ± 5 | 3.1 ± 0.5 | 5.2 ± 0.4(13/3) | 1.2 ± 0.2 | 10 ± 1.0 | 24 ± 1.6 |
+/- | 42 ± 4 | 2.9 ± 0.6 | ND | 1.1 ± 0.2 | ND | ND |
-/- | 43 ± 7 | 3.2 ± 0.5 | 4.3 ± 0.7(12/2) | 1.1 ± 0.3 | 9 ± 0.9 | 23 ± 1.3 |
Data are shown as mean ± SEM (n junctions/n mice). ND, Not determined. No significant differences were observed across genotypes (p > 0.2; Student's t test).