Figure 3.

Histological and neurochemical characterization of intrastriatal 6-OHDA lesions. Representative image of the brain regions analyzed (a), using coronal sections of the mice’s brains. Brightfield photomicrographs of representative coronal brain sections stained for TH (b). Compared to the vehicle group, 6-OHDA animals presented marked reduction of TH+ labelling into the dorsal striatum (c) and NAc (d), as well as significant loss of TH+ cells in the SNpc (e) and VTA (f). HPLC quantification, combined with electrochemical detection, showed a significant decrease of DA and its metabolite DOPAC in both dorsal striatum (g) and NAc (h), after 6-OHDA administration. No differences were found between groups for the monoamines and its derivates (NE, 5-HT, and 5-HIAA), for both regions (g,h). For the dorsal striatum, the reduced levels of DA were accompanied with an increased DA turnover in this brain region (i) (Student’s t-test; statistical summary in Table S1; data are presented as mean ± SEM and as % of contralateral side). For histological analysis vehicle n = 9, 6-OHDA n = 11; for HPLC vehicle = 4–5, 6-OHDA n = 6–7. * p < 0.05, ** p < 0.01, *** p < 0.001. Scale bar = 1 mm. Abbreviations: dSTR, dorsal striatum; DA, dopamine; DOPAC, 3,4-dihydroxyphenylacetic acid; NAcC, nucleus accumbens core; NAcS: nucleus accumbens shell; NE, norepinephrine; SNpc, substantia nigra pars compacta; TH, tyrosine hydroxylase; VTA, ventral tegmental area; 5-HIAA, 5-hydroxyindoleacetic acid; 5-HT, serotonin; 6-OHDA, 6-hydroxydopamine.