Table 1.

Percentage of NMJ defects as the disease progresses between P2 and P14 in SMA mice with increasingly severe phenotypes

		P2	P8 (P5)	P14
Δ7+/−	Proximal (abd.)	44.2 ± 9.0% (+ −)	95.5 ± 4.0% (+ +) at P5	–
	Distal (gastroc.)	19.0 ± 4.0% (+ −)	81.9 ± 5.0% (+ +) at P5	–
Δ7+/+	Proximal (abd.)	10.3 ± 5.1% (+ −)	69.0 ± 11.5% (+ +)	87.3 ± 9.5% (+ +)
	Distal (gastroc.)	0% (− −)	67.5 ± 9.5% (+ +)	92.7 ± 3.0% (+ +)
A2G	Proximal (abd.)	0% (− −)	27.6 ± 6.9% (+ +)a	68.0 ± 2.8% (+ +)a
	Distal (gastroc.)	0% (− −)	9.5 ± 5.6% (+ +)a	57.6 ± 3.0% (+ +)a

Note: Oblique abdominal muscle (abd.) and the gastrocnemius (gastroc.) served as representative proximal and distal muscles, respectively, in this analysis. Δ7^+/−, Δ7^+/+ and A2G refer to the genotypes of the SMA mice as described in the main text. Symbols in parentheses represent pre- and post-synaptic defects respectively with ‘+’ indicating the presence of, and ‘−’, the absence of defects. Pre-synaptic defects include poor terminal arborization, NF accumulation in nerve terminals and/or pre-terminal axons; post-synaptic defects include AChR clusters of reduced complexity, smaller endplates and weakly staining AChRs indicating disassembly/dispersal of the receptors at the NMJ.

^aIndicates that the pre-synaptic defects are restricted to poor terminal arborization, n ≥ 2.