NEUROTROPHIN-LIKE IMMUNOREACTIVITY IN THE HUMAN TRIGEMINAL GANGLION

THE localization of the neurotrophins nerve growth factor (NGF), brain -derived neurotrophic factor (BDNF), neurotrophin-dr (NT-4), and neuro trophin-3 (NT-3) was demonstrated immunohistochemically in discrete ne uronal subsets of the human trigeminal ganglion at ages ranging from 2 3 weeks of gestation to adulthood. Neurotrophin-containing subpopulati ons partially overlapped with each other and with those immunoreactive for the relevant trk receptor. Glial elements could also be immunosta ined, labelled satellite cells being particularly abundant in NT-3 sta ined sections. These results suggest that the neurotrophins are of fun ctional significance for the human trigeminal primary sensory neurones throughout life. Their localization in the ganglion cellular componen ts supports their function as target-derived trophic factors and as mo lecules effective in autocrine/paracrine interactions.