Figure 4. Effects of HU on minimum and maximum steady-state firing frequencies.

Significant interaction effects were found for minimum (A, P = 0.009) and maximum (B, P = 0.014) steady-state firing frequencies. For both measures, slow motoneurones in weight-bearing rats had significantly lower steady-state firing frequencies than all other groups; thus, slow motoneurones in unweighted rats had steady-state firing frequency ranges similar to fast motoneurones.