efficiacy of rotational and swing tests in evaluation of more asymmetry in hemiparkinsonian rats

introduction: animal models of parkinson’s disease (pd) with partial damage of nigrostriatal dopaminergic system are very suitable for development of treatment strategies. although drug-induced rotational behavior has been conventionally used for analysis of lesioned animals, but bcause of the development of sensitization, it is necessary to invent a pure behavioral test that can evaluate such animals in a drug-free state which may better reflect a more natural response of the animal following lesion. this study was conducted to evaluate the efficiency of elevated-body swing test in analysis of unilaterally lesioned animals in an early model of parkinson’s disease. material and methods: thirty male rats were randomly divided into sham-operated and lesion groups. an early model of pd was developed by interstitial injection of 12.2 microg of 6-hydroxydopamine (6-ohda) into the left striatum. apomorphine-induced rotational and drug-free elevated body swing behaviors were evaluated. results: results of behavioral tests revealed that apomorphine caused a very significant contralateral turning in the rats of the lesion group (l+v) compared to sham-operated group (sh) (p<0.0001). in addition, there existed a significant difference between +v and sh groups in the second (p<0.01) and fourth weeks (p<0.05) after surgery. further analysis of correlation for not number of rotations versus net number of rotations versus net number swings revealed a significant and positive correlation (r=0.52) in the second week in l+v group, but no such correlation was observed in the fourth week (r=0.24). conclusion: taken together, it is concluded that elevated body swing test may be of less value in evaluation of motor asymmetry in an early model of parkinson’s disease compared to drug-induced rotational behavior. therefore, it may be used as a complementary test to drug-induced rotational test for alternate evaluation of motor asymmetry in unilateral model of early pd in rats.