Fig. 4

Dopaminergic, serotonergic and noradrenergic centers do not show significant neurodegeneration or glial activation in the rotenone model in the rat. Dopaminergic neurons marked by tyrosine-hydroxylase (TH, green) labeling in the ventral tegmental area (VTA) (A, B) and dorsal raphe nucleus (DR) (E, F) do not show significant neurodegeneration as shown by histograms C and G, respectively. The number of ionized calcium binding adaptor molecule 1 (IBA1, red in A, B, E, F)-ir microglia-TH neuron interactions remained unchanged both in the VTA (D) and DR (H) upon rotenone treatment. The number of serotonin (5-HT)-producing neurons of the DR (green, I, J) and median raphe nuclei (MNR, green, M, N) were not affected significantly as shown in panel (K) and (O), respectively. The number of microglia (IBA1, red in I, J, M, N)—5-HT neuron interactions did not change in the DR (L) and MNR (P). Noradrenergic cells of the locus ceruleus (LC, Q, R) and A5 noradrenergic cells of the ventrolateral medulla (U, V) shown by TH immunolabeling (green) did not suffer significant neurodegeneration upon rotenone treatment as shown in histograms (S) and (W), respectively. The microglial activity score (IBA1, red in Q, R, U, V) did not change in the LC (T) and in the A5 (X). 4th: fourth brain ventricle. Black bars: vehicle (oil) injected rats, red columns: rotenone-treated group. n = 7-12. Bars: 50 µm