A transient afferent innervation of outer hair cells in the postnatal cochlea.

In vitro retrograde labeling techniques were used to reconstruct the peripheral terminations of afferent fibers to the outer hair cells in postnatal hamsters. Between postnatal days 4 and 6, both radial and spiral afferent fibers terminated on outer hair cells. The cell bodies which gave rise to such fibers were not distinguishable. These outer radial-fiber terminations may be a transient phenomenon since they were not observed either before or after this period.