Two praxiological methods in evaluation the substantia nigra compacta lesion size of rats

Objective To observe the characteristics of praxiology and morphology of 6-hydroxydopamine(6-OHDA) lesioned rats and the relation between them;and to seek a sensitive behavioral parameter in evaluation DA degenerative degree.MethodsRats received a unilateral injection of 6-OHDA into the substantia nigra pars compacta (SNc).Behavioral changes and dopaminergic degeneration were observed with the open-field test,apomorphine(APO) induced turning,HE and Nissl body staining,and immunocytochemistry methods 1d,3d,5d,7d,14d,21d after lesion.ResultsNearly 50% dopaminergic neurons lossed in ipsilateral SNc on 1d while approximately 90% on 21d.All parameters of open-field test except grooming had a notable alternation 1d after lesion(P0.05).The correlational analyses yielded a positive relationship between turning and lesion size(r=0.471,P0.01),while scanning、rearing and locomotor activity were negatively correlated with lesion size(r=-0.719,r=-0.589,r=-0.594,P0.01).There was an obvious tendency of recovery on 3d and 5d.APO induced turning commenced 7d after lesion,which the velocity exceeded 7circles/min on 14d,and positively correlated with DA level(r=0.942,P0.01),but no recovery exhibited.ConclusionThe open-field test is a sensitive behavioral parameter to predict degree of DA deletion.