Observation on the localization of mechanoreceptors in the kidney and afferent nerve fibres in the renal nerves in the rabbit.

1. The distribution and localization of mechanoreceptors in the kidney were studied by recording afferent impulses from the renal nerve bundle or from single nerve fibres in the isoloted kidney preparation in the rabbit. 2. It was observed that mechanoreceptors are distributed in the cranial, central and caudal portions as well as the pelvic portion of the kidney. Diameter range of single nerve fibres from which afferent impulses were recorded was from 2 to 8 mum. 3. Histological studies show that the renal nerve possesses abundant non-myelinated nerve fibres with a relatively small number of myelinated nerve fibres. The myelinated axons had diameters ranging from 0-5 to 13-4 mum and the peak of the unimodal distribution curve was 1-5--2-4 mum.