کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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6019301 | 1186548 | 2010 | 8 صفحه PDF | دانلود رایگان |
In the dopamine-depleted striatum, an altered post-synaptic signalling of efferent neurons might underline the onset of variable dyskinetic responses to dopaminergic agonists. We have previously shown that a subchronic treatment with the D1 agonist SKF-38393 and the D2 agonist ropinirole induces a dyskinetic response of high and low intensities respectively, in 6-hydroxydopamine-lesioned rats. Here, zif-268 mRNA expression was evaluated in striatonigral and striatopallidal neurons to assess a neurochemical marker of these different dyskinetic responses upon drug administration. Acute and subchronic SKF-38393 (3Â mg/kg) increased zif-268 expression per neuron in the striatonigral pathway, albeit the number of neurons displaying high early-gene levels was reduced by the subchronic treatment. Zif-268 mRNA in striatopallidal neurons was not affected by SKF-38393 treatments. In contrast, ropinirole (5Â mg/kg) did not alter zif-268 mRNA in striatonigral neurons acutely, whereas ropinirole decreased zif-268 mRNA subchronically. Both acute and subchronic ropinirole decreased zif-268 levels in the striatopallidal pathway. The differential expression of zif-268 in striatonigral and striatopallidal neurons might provide a biochemical correlate of the dyskinetic outcome displayed by SKF-38393 and ropinirole treatments, suggesting that evaluation of neuronal responses upon drug administration provides a tool for the preclinical characterization of dyskinetic potential beyond behavioural tests.
Journal: Experimental Neurology - Volume 224, Issue 2, August 2010, Pages 395-402