RT Journal Article SR Electronic T1 GDNF Protection against 6-OHDA: Time Dependence and Requirement for Protein Synthesis JF The Journal of Neuroscience JO J. Neurosci. FD Society for Neuroscience SP 7111 OP 7118 DO 10.1523/JNEUROSCI.17-18-07111.1997 VO 17 IS 18 A1 Kearns, Cecilia M. A1 Cass, Wayne A. A1 Smoot, Kyle A1 Kryscio, Richard A1 Gash, Don M. YR 1997 UL http://www.jneurosci.org/content/17/18/7111.abstract AB Glial cell line-derived neurotrophic factor (GDNF) injected intranigrally protects midbrain dopamine neurons against 6-hydroxydopamine (6-OHDA) toxicity. The timing between GDNF administration and exposure to 6-OHDA is critical in achieving optimal protection. When injected 6 hr before an intranigral injection of 6-OHDA, GDNF provides complete protection as measured by the number of surviving neurons in the substantia nigra of adult rats. The surviving neuronal population decreases by ∼50% with 12 and 24 hr separating GDNF and 6-OHDA administrations. In controls with 6-OHDA lesions, there is <10% survival of nigral dopamine neurons. No significant increase in survival is seen with either concurrent injections of GDNF and 6-OHDA or 1 hr GDNF pretreatment. Based on HPLC measurements, striatal and midbrain dopamine levels are at least twofold higher on the lesioned side in animals receiving GDNF 6 hr before a 6-OHDA lesion compared with vehicle recipients. Protein synthesis is necessary for GDNF-induced neuroprotective effects because cycloheximide pretreatment that inhibits protein synthesis also blocks neuroprotection.