Table 3.

Fos expression in spinal cord 16 d after acid injection

	Wild type			Wild type NT-3 treated
	Contralateral	Ipsilateral	Contralateral	Ipsilateral
Lamina I-II	3.8 ± 0.86	10.6 ± 0.93*	1.25 ± 0.35	2.45 ± 0.42
Lamina III-IV	4.6 ± 0.68	11.8 ± 0.58*	1.80 ± 0.49	3.55 ± 0.73
Lamina V-VI	5.0 ± 1.05	7.8 ± 1.07*	2.60 ± 0.62	3.65 ± 0.39

The number of Fos-positive cells was counted from different spinal laminas from both ipsilateral and contralateral sides of the spinal cord 16 d after acid injection. Comparisons were made between groups using one-way ANOVA and Fisher's PLSD. In wild-type mice, acid injection caused a significant increase in the number of Fos-positive neurons compared with wild-type mice receiving NT-3 treatment for 10 d in each lamina (^*p < 0.05). Fos expression in wild-type NT-3-treated mice confirmed that cessation of NT-3 treatment 10 d after the initial acid injection correlates with a lack of Fos activity 1 week later. Data are plotted as means ± SEM; n = 3 animals per group.