Table 2.

Percentage of P0 DRG neurons expressing TrkB or TrkC in wt and NT-4 mutant mice

	% of TrkB (+) neurons	% of TrkC (+) neurons
wt	11.3  ± 0.3%	7.8  ± 0.8%
NT-4 −/−	1.2  ± 0.4%	16.8  ± 0.5%
P value	P < 0.0001	P < 0.0001

Percentage of TrkB- and TrkC-expressing neurons of the lumbar DRG were counted in sections of the midganglia in wt and NT-4 mutant mice. The number of Trk-positive neurons (Fig. 3 a–j) was compared with total neuron counts (≈2,000–4,000 neurons) in the same lumbar sections (10 sections per animal). Student's t test determined the significance levels. n = 4.