GFAP EXPRESSION IN LUMBAR SPINAL-CORD OF NAIVE AND NEUROPATHIC RATS TREATED WITH MK-801

The objective of the present investigation was to determine if baselin e glial fibrillary acidic protein (GFAP) expression and the increases in GFAP expression induced by chronic constriction of the sciatic nerv e were modified by the specific N-methyl-D-aspartate (NMDA) receptor a ntagonist MK-801. Changes in immunohistochemical staining densities of GFAP within the L4 spinal cord were quantified and compared in three groups of animals: (1) nonneuropathic rats, (2) nondrug-treated neurop athic rats, and (3) neuropathic rats treated for 7 days with MK-801. T he results indicate that baseline GFAP staining density in naive anima ls is dependent on NMDA receptor activity and that an ongoing NMDA-dep endent signal is, at least in part, responsible for the increase in GF AP observed following-peripheral nerve injury. (C) 1994 Academic Press , Inc.