High-frequency stimulation of the globus pallidus interna nucleus modulates GFRα1 gene expression in the basal ganglia

Deep brain stimulation (DBS) is an established therapy for movement disorders such as Parkinson's disease (PD). Although the efficacy of DBS is clear, its precise molecular mechanism remains unknown. The glial cell line derived factor (GDNF) family of ligands has been shown to confer neuroprotective effects on dopaminergic neurons, and putaminal infusion of GDNF have been investigated in PD patients with promising results. Despite the potential therapeutic role of GDNF in alleviating motor symptoms, there is no data on the effects of electrical stimulation on GDNF-family receptor (GFR) expression in the basal ganglia structures. Here, we report the effects of electrical stimulation on GFR alpha 1 isoforms, particularly GFR alpha 1a and GFR alpha 1b. Wistar rats underwent 2 hours of high frequency stimulation (HFS) at the globus pallidus interna nucleus. A control group was subjected to a similar procedure but without stimulation. The HFS group, sacrificed 24 hours after treatment, had a threefold decrease in mRNA expression level of GFR alpha 1b (p = 0.037), but the expression level reverted to normal 72 hours after stimulation. Our preliminary data reveal the acute effects of HFS on splice isoforms of GFR alpha 1, and suggest that HFS may modulate the splice isoforms of GFR alpha 1a and GFR alpha 1b to varying degrees. Going forward, elucidating the interactions between HFS and GFR may shed new insights into the complexity of GDNF signaling in the nervous system and lead to better design of clinical trials using these signaling pathways to halt disease progression in PD and other neurodegenerative diseases. (C) 2013 Elsevier Ltd. All rights reserved.