Abstract
The present study describes a method to inhibit selectively the microglial cell proliferation following peripheral nerve injury. Continuous infusion of cytosine‐arabinoside (ARA‐C) from an osmotic minipump to the fourth ventricle or cisterna magna completely blocks the proliferation of microglial cells that normally occurs following hypoglossal nerve transection. This treatment had no significant effect on other glial cells or on the expected morphological changes in the axotomized hypoglossal motorneurons. The method opens up new possibilities for analyzing the functional role of the axotomy‐induced microglial cell reaction.