Effects of neurotrophin and neurotrophin receptor disruption on the afferent inner ear innervation.
Two neurotrophins and their two receptors appear to regulate the survival of vestibular and cochlear neurons in the developing ear. Mice lacking either brain derived neurotrophic factor (BDNF) or its associated receptor, Trk B, show a severe reduction in the number of vestibular neurons and a loss of all innervation to the semicircular canals. Mice lacking NT-3 or its receptor, Trk C, show a severe reduction of spiral neurons in the basal turn of the cochlea. Mice lacking both BDNF and NT-3 or Trk B and Trk C, reportedly lose all innervation to the inner ear. These two neurotrophins and their associated receptors are necessary for the normal afferent innervation of the inner ear.
Fritzsch
B
B
Department of Biomedical Sciences, Creighton University, Omaha, NE 68178, USA.
Silos-Santiago
I
I
Bianchi
L M
LM
Farinas
I
I
D000818:Animals; D019208:Brain-Derived Neurotrophic Factor / Q000172:deficiency / Q000235:genetics / Q000502:physiology*; D003051:Cochlea / Q000196:embryology / Q000294:innervation / Q000378:metabolism / Q000648:ultrastructure; D007758:Ear, Inner / Q000196:embryology / Q000294:innervation* / Q000378:metabolism / Q000648:ultrastructure; D018507:Gene Expression Regulation, Developmental; D006198:Hair Cells, Auditory / Q000196:embryology / Q000502:physiology / Q000648:ultrastructure; D051379:Mice; D008817:Mice, Mutant Strains; D008854:Microscopy, Electron; D009475:Neurons, Afferent / Q000378:metabolism / Q000502:physiology / Q000648:ultrastructure; D020933:Neurotrophin 3 / Q000187:drug effects / Q000235:genetics / Q000502:physiology*; D020813:Receptor, trkB / Q000172:deficiency / Q000235:genetics / Q000502:physiology*; D020812:Receptor, trkC / Q000172:deficiency / Q000235:genetics / Q000502:physiology*; D012444:Saccule and Utricle / Q000196:embryology / Q000294:innervation / Q000378:metabolism / Q000648:ultrastructure; D012665:Semicircular Canals / Q000196:embryology / Q000294:innervation / Q000378:metabolism / Q000648:ultrastructure
D019208:Brain-Derived Neurotrophic Factor; D020933:Neurotrophin 3; D020813:Receptor, trkB; D020812:Receptor, trkC