The distribution of enkephalin-like immunoreactivity in the cochlea of the @entity840 and cat was studied. Indirect immunofluorescence immunohistochemistry using antisera generated against a @entity1853 enkephalin- @entity291 thyroglobulin conjugate was applied to surface preparations of the organ of Corti and cryostat sections of the whole of the cochlea. In the cochlear osseous spiral lamina, immunofluorescence was localized to unmyelinated fibers of the intraganglionic spiral bundle. In the organ of Corti, immunofluorescence was localized to a small number of fibers at inner hair cells, the inner spiral bundle, and tunnel spiral bundle, to tunnel crossing fibers at the level of the tunnel floor, to an occasional spiral outer fiber, and to the synaptic region of outer hair cells in the three rows of the basal turn of the cochlea. Less immunofluorescence was found in this region as one progressed towards the apex, with none seen at the apex. At the most apical region the inner spiral bundle became patchy and the tunnel spiral bundle developed arcades. There was no immunofluorescence found in spiral ganglion cells, in @entity2167 , or in the hair cells of the organ of Corti. The findings were the same in cat as in @entity840 , the latter being studied in more detail. It was concluded that efferent, olivocochlear neurons of the cochlea, synapsing predominantly with primary @entity2167 from the inner sensory cells or with the sensory cells, contain enkephalin-like immunoreactivity. Also, the findings indicate that endings of olivocochlear neurons that synapse predominantly with outer hair cells contain enkephalin-like immunoreactivity. It has previously been shown that olivocochlear neurons are likely to be cholinergic.

Enkephalin-like immunoreactivity of olivocochlear nerve fibers in cochlea of XXXX and cat.

@entity840 :: ('10141', 'Species') :: ['guinea pig'] @entity291 :: ('9913', 'Species') :: ['bovine'] @entity2167 :: ('MESH:D006311', 'Disease') :: ['auditory nerve fibers'] @entity1853 :: ('MESH:D008715', 'Chemical') :: ['methionine']
@entity840 :: (10141,Species) :: ['guinea pig']
