Figure 2
Microphotographs showing fibroblast growth factor (FGF-2) immunoreactivity in coronal sections of rat facial nucleus. Animals were submitted to the following procedures and sacrificed 7 days later: a transection of the facial nerve (with amputation of the nerve stumps) (B, D) or a sham operation (A, C); a 7-days systemic treatment of corticosterone (daily ip. injection of 10 mg × kg-1, corticosterone) (E) or solvent (F); a 7-days unilateral functional electrical stimulation of the levator labii superioris muscle after a local implantation of a mononylon thread electrode (1 mA current, 30 Hz frequency square wave) (G) or without current as control (H). The facial nerve was not lesioned in the corticosterone and electrical stimulation experiments. The figures C and D represent higher magnification of areas inside the nuclei showed in figure A and B, respectively. The FGF-2 immunoreactivity is seen in the cytoplasm of neurons (arrows) and in the nuclei of glial cells (arrowheads), respectively. It is observed that the transection of the facial nerve and also systemic corticosterone increased the FGF-2 immunoreactivity in the nuclei of glial cells in facial nuclei ipsilateral to the injury and bilaterally after drug injection. The functional electrical stimulation of the levator labii superioris led to increase of FGF-2 mainly in the cytoplasm of neurons of facial nucleus ipsilateraly. Bars = 50 μm (A, B), 25 μm (C-H).