GLIAL CELL-LINE DERIVED NEUROTROPHIC FACTOR (GDNF) MESSENGER-RNA UP-REGULATION IN STRIATUM AND CORTICAL AREAS AFTER PILOCARPINE-INDUCED STATUS EPILEPTICUS IN RATS

Glial cell-line derived neurotrophic factor (GDNF) has recently been c loned and shown to have trophic effects on dopaminergic nigral neurons . However, GDNF mRNA has not been detected in striatum or other forebr ain areas of adult rat. Using limbic motor status epilepticus induced by pilocarpine to activate neurons in motor and limbic areas, we now d emonstrate GDNF mRNA signals in the striatum, hippocampus and cortex u sing in situ hybridisation. The finding of GDNF mRNA in the stimulated striatum opens the possibility that GDNF may be a target-derived, tro phic factor in the nigro-striatal system. This expression of GDNF mRNA may be linked to excitatory cortical input. Increases in GDNF mRNA af ter status epilepticus in hippocampus and neocortex indicate additiona l roles for GDNF.