Facial nerve lesion response; strain differences but no involvement of IFN-gamma, STAT4 or STAT6.

Facial nerve lesions lead to a retrograde response characterized by activation of glia surrounding axotomized motoneurons and up-regulation of immunological cell surface molecules such as major histocompatibility complex (MHC) antigens. Cytokines, in particular interferon-gamma, are potent inducers of MHC expression and glial activation. We have here tested whether axotomy-induced activation is changed in transgenic mouse strains lacking components of the IFN-gamma signaling pathway, STAT4 or STAT6.