Selective expression of peripherin in gonadotropin-releasing hormone-synthesizing neurons of the rat

Immunofluorescent double stainings for gonadotropin-releasing hormone (GnRH) and peripherin, vimentin, or neurofilament-70 were used to determine the identity of the intermediate filaments in GnRH neurons of the adult rat. The results show that GnRH cells are unique neurons in the septum-rostral hypothalamus in that they express peripherin and vimentin but not neurofilament-70. Both peripherin and vimentin form a dense perinuclear network from which peripherin extends only into the proximal neurites, while vimentin can be seen in certain GnRH terminals in the median eminence. The presence of peripherin and vimentin in GnRH neurons as well as in olfactory receptor neurons suggests close ties between these cell types and supports the view that both cell types arise from a common ancestor.