Dopamine analysis. The left, untreated side of the brain retained the highest dopamine level and was different from all right side levels. The difference was significant between the recovered and nonrecovered animals (**, p < .05). There was no difference (p > .1, NS) between TRecov and PreTRecov animals or between TNoRecov and PreTNoRecov animals. Abbreviations: NS, not significant; PreTNoRecov, nontransfected nonrecovered; PreTRecov, nontransfected recovered; TNoRecov, transfected nonrecovered; TRecov, transfected recovered.