Glial cell-line derived neurotrophic factor (GDNF) mRNA upregulation in striatum and cortical areas after pilocarpine-induced status epilepticus in rats.

Glial cell-line derived neurotrophic factor (GDNF) has recently been cloned and shown to have trophic effects on dopaminergic nigral neurons. However, GDNF mRNA has not been detected in striatum or other forebrain areas of adult rat. Using limbic motor status epilepticus induced by pilocarpine to activate neurons in motor and limbic areas, we now demonstrate GDNF mRNA signals in the striatum, hippocampus and cortex using in situ hybridisation. The finding of GDNF mRNA in the stimulated striatum opens the possibility that GDNF may be a target-derived, trophic factor in the nigro-striatal system. This expression of GDNF mRNA may be linked to excitatory cortical input. Increases in GDNF mRNA after status epilepticus in hippocampus and neocortex indicate additional roles for GDNF.