Unilateral 6-Hydroxydopamine Lesions of Nigrostriatal Dopaminergic Neurons Increased Cannabinoid CB1 Receptor mRNA Levels in the Rat Striatum: Possible Therapeutic Implications
It has been recently suggested that the effects of cannabinoids on motor behavior might be different in rats with lesions of the basal ganglia than controls. In the present study, we have examined the possible alteration in the status of cannabinoid CB1 receptors in the basal ganglia of rats with unilateral lesions of nigrostriatal dopaminergic neurons caused by 6-hydroxydopamine, an animal model of Parkinson’s disease. As expected, lesioned rats exhibited a marked reduction in tyrosine hydroxylase-mRNA levels, measured by in situ hybridization, in the substantia nigra of the lesioned side. Lesioned rats also exhibited the characteristic rotational behavior after a single injection of apomorphine. Interestingly, we also found a significant increase in levels of CB1 receptor-mRNA transcripts in the lesioned side in both the lateral and medial caudate-putamen, which supports a critical role for dopamine in the control of CB1 receptor gene expression in striatal efferent neurons. This also suggests that CB1 receptor antagonists might be useful to improve movement in Parkinson’s disease.
KeywordsToxicity Dopamine Tyrosine Neurol Peri
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