Basal microdialysis measurements. Basal DA metabolite levels measured by microdialysis in the striatum, estimated using in vitro probe recoveries. (A) Results for striatum ipsilateral to the 6-OHDA lesion. (B) Results for striatum contralateral to the 6-OHDA lesion. The asterisk indicates significant difference from the unlesioned control group, and the number sign indicates significant difference from the <80% lesion group (p < 0.05). For unlesioned control rats, data from the left and right striata were averaged. Error bars represent standard errors on the mean.