Dopamine receptor gene transfer into rat striatum using a recombinant adenoviral vector: rotational behaviour

To study the role of dopamine (DA) receptor expression on dopamine-mediated rotational behaviour, adenovirus expressing the lacZ reporter gene (AdCMVLacZ) or D2R expressing adenoviral vector (AdRSVD2) viruses, mediating expression of beta-galactosidase and DAD2 receptors, respectively, were microinjected stereotactically into Sprague-Dawley rat striatum. Apomorphine stimulated rotational behaviour was measured in rats unilaterally injected with either AdCMVLacZ or AdRSVD2. No significant difference in rotational direction was observed until day 14 post-injection, when animals showed a tendency to rotate away from the injected side. Our data indicate that unilateral changes in receptor density mediated by a non-cell type selective adenoviral vector results in minor changes in rotational behavior. This suggests that supersensitivity in dopamine receptor signaling, rather than receptor levels per se, are the major factor in determining rotational response with dopamine agonist stimulation in unilateral striatal dopamine depleted animals.