FACIAL-NERVE LESIONS LEAD TO INCREASED IMMUNOSTAINING OF THE ASTROCYTIC GAP JUNCTION PROTEIN (CONNEXIN 43) IN THE CORRESPONDING FACIAL NUCLEUS OF RATS

After peripheral transection of the facial nerve, immunostaining of as trocytic gap junction protein changed in the corresponding brainstem n ucleus of the rat. Enhanced connexin-43 immunoreactivity was restricte d to the ipsilateral facial nucleus and to astrocytes surrounding lesi oned motoneurons. This reaction is focally distinct, and marks only a part of the astrocytic network indicating a local plasticity of interc ellular coupling. These results suggest that astrocytes work as sensor s of signals which either depend on the integrity of neighboring neuro ns or inform about neuronal disorders.