Changes in the expression and localization of signaling molecules in mouse facial motor neurons during regeneration of facial nerves

•Two months after operation of facial nerves, function was almost recovered.•ChAT-positive neuron number decreased at day 7, and recovered by day 60.•Elevated expression of galanin and CGRP returned by days 28 and 60, respectively.•Expression of gephyrin and KCC2 decreased after surgery, and recovered by day 60.•CGRP, ChAT, and KCC2 may be objective indicators of axonal regeneration.