The unmyelinated nerve fibres of the cochlea

A quantitative analysis was made of the unmyelinated nerve supply to the cochlea in normal cats and after various nerve lesions with different survival times. The normal fibre distribution in the intraganglionic spiral bundle (IGSB) and the osseous spiral lamina (OSL) varies characteristically along the cochlear turns. The unmyelinated nerve fibres are mainly associated with the IGSB and originate partly in the superior cervical ganglion and partly in the brain stem. They seem to have an excellent capacity to regenerate.