EFFECTS OF NEUROTROPHIN AND NEUROTROPHIN RECEPTOR DISRUPTION ON THE AFFERENT INNER-EAR INNERVATION

Two neurotrophins and their two receptors appear to regulate the survi val of vestibular and cochlear neurons in the developing ear Mice lack ing either brain derived neurotrophic factor (BDNF) or its associated receptor Trk B, show a severe reduction in the number of vestibular ne urons and a loss of all innervation to the semicircular canals. Mice l acking NT-3 or its receptor Trk C, show a severe reduction of spiral n eurons in the basal turn of the cochlea. Mice lacking both BDNF and NT -3 or Trk B and Trh C, reportedly lose all innervation to the inner ea r These two neurotrophins and their associated receptors are necessary for the normal afferent innervation of the inner ear.