Quantitative mapping of cutaneous receptive fields in normal and operated leeches, Limnobdella.

1. The receptive fields and physiological properties of the sensitive cutaneous mechanoreceptive neurones in the leech Limnobdella australis were found to be very similar to those previously described in Hirudo medicinalis. 2. Following separation from the central nervous system (C.N.S.), the distal dendrite stump and cutaneous receptive field remained unchanged for at least 160 days. 3. There was little spreading of receptive fields into regions of skin isolated from the C.N.S. for at least 184 days. 4. Cutting one dendrite of a mechanoreceptive neurone which has two major dendrites produced little change in the receptive field of the intact dendrite. 5. Abnormalities were found in most of the receptive fields of operated leeches, irrespective of the site of operation. These abnormalities were not seen in normal leeches.