FIGURE 2.

Reduction of dopamine and noradrenergic levels in a model of pre-motor PD. (A) Representative images of TH-staining in the substantia nigra pars compacta (SNc) in the sham-operated animals (top panel), pre-motor model (middle panel), and model treated with EX-4 (bottom panel). Scale bars represent 500 μm. (B) Number of TH-positive cells in the SN expressed as cell density per mm³ (n = 6 animals per experimental group). A decrease in the number of TH-positive cells was observed in the pre-motor model (unpaired t-test ^∗∗P < 0.01). This decrease was partially prevented by treatment with EX-4 (unpaired t-test P_{sham vs. model + EX-4} >0.05; P_{model vs.model + EX-4} >0.05). (C) HPLC measurements of tissue levels of dopamine (DA) in SN, striatum and piriform cortex (PC) expressed as ng/g wet weight. Levels of DA were reduced in the three regions (unpaired t-test n = 4–5 animals per group ^∗∗P < 0.01, ^∗∗∗∗P < 0.0001). (D) HPLC measurements of tissue levels of noradrenaline (NA) in SN, striatum and piriform cortex (PC) expressed as ng/g wet weight. Levels of NA were reduced in the three regions (unpaired t-test n = 4–5 animals per group ^∗∗∗P < 0.001).