FIGURE 6.

Nerve injury causes down-regulation and cleavage of KCC2 and changes in synaptic inhibition and E_glycine of lamina II neurons through calpain activation. a, perforated recordings show the EPSP spike activity of lamina II neurons before and during bath application of 2 μm strychnine in spinal slices of SNL rats preincubated with calpeptin (30 μm, 3 h; n = 7). b, I-V plots show changes in E_glycine of lamina II neurons from slices of SNL rats incubated with calpeptin (n = 7) or vehicle (1% DMSO, n = 9) and slices of control rats incubated with NMDA plus calpeptin (n = 6). V_H, holding potential. c, shown are Western blots (left) and quantification (right) of the KCC2 protein levels in dorsal spinal cord slices of control rats treated with NMDA (30 μm for 3 h) or NMDA plus AP5 (50 μm for 3 h) (n = 5 in each group). NT, N-terminal. d, shown are Western blots (top) and quantification (bottom) of the total KCC2 amount in dorsal spinal cords ipsilateral (Ipsi) and contralateral (Cont) to SNL in rats treated with intrathecal administration of calpeptin (n = 7) or vehicle (1% DMSO, n = 8). e, shown are immunoblots (top) and quantification (bottom) of the KCC2 amount and fragment (∼120 kDa) in the plasma membrane and cytosol fractions of dorsal spinal cords ipsilateral (Ipsi) and contralateral (Cont) to SNL in rats treated with intrathecal administration of calpeptin (n = 6) or vehicle (1% DMSO, n = 6). KCC2 was detected by using KCC2 N terminus antibody. *, p < 0.05, Kruskal-Wallis test. Error bars represent S.E.