The dendrites of spinal motoneurones are highly active, generating a strong persistent inward current (PIC) that has an enormous impact on synaptic integration. The PIC is subject to regulation by descending neuromodulatory systems releasing the monoamines serotonin and norepinephrine. At high monoaminergic drive levels, the PIC dominates synaptic integration, generating an intrinsic dendritic current that is as much as 5-fold larger than the current entering via synapses. In contrast, motoneurones lacking significant PICs are virtually non-excitable. Presumably, this descending control of the synaptic integration via the PIC is used to adjust the excitability (gain) of motoneurones for different motor tasks. A problem with this gain control is that monoaminergic input to the cord is very diffuse, affecting many motor pools simultaneously, likely including both agonists and antagonists. The PIC is, however, exquisitely sensitive to the reciprocal inhibition mediated by length sensitive muscle spindle Ia afferents and Ia interneurons. Reciprocal inhibition is tightly focused, shared only between strict mechanical antagonists, and thus can act to "sculpt" specific movement patterns out of a background of diffuse neuromodulation. Thus it is likely that motoneurone gain is set by the interaction between diffuse descending neuromodulation and specific and local synaptic inhibitory circuits.