Recovery of mimic function after facial nerve transection is poor: the successful regrowth of axotomized motoneurons to their targets is compromised by (i) poor axonal navigation and excessive collateral branching, (ii) abnormal exchange of nerve impulses between adjacent regrowing axons and (iii) insufficient synaptic input to facial motoneurons. As a result, axotomized motoneurons get hyperexcitable and unable to discharge. Since improvement of growth cone navigation and reduction of the ephaptic cross-talk between axons turn out be very difficult, the authorsa concentrated on the third...