Fig. 2

dsRed-expressing WEEV (McRed) shows strong tropism for dopaminergic neurons and causes selective dopaminergic neuronal loss and glial activation following intranasal inoculation. a–d Neuronal densities in hippocampus and entorhinal cortex were examined at 4 DPI following intranasal infection with McRed. No significant neuronal loss was detected in the hippocampus (CA1) or the entorhinal cortex (338 ± 6.557 vs. 342.8 ± 9.259, p = 0.7142 and 101.3 ± 6.96 vs. 90.4 ± 18.1, p = .6730) (N = 4/group). e–g Sagittal and coronal sections from CLARITY processed brains (h–j) were immunostained for TH + dopaminergic neurons. High-magnification confocal images (k–n) demonstrate co-localization of DsRed (red) and TH + DA neurons (green). White dotted regions delineate the substania nigra pars compacta (SN). n X and Y coordinates in top panel with X and Z coordinates in lower panel. o Number of DA neurons in SNpc were examined with 3D design-based stereology 4 DPI. A 29% loss of DA was observed between treatment groups. (29% loss, 8707 ± 202.2 vs. 6180 ± 162.6). Intense staining for IBA1-positive microglia (green) (p) and GFAP-positive astrocytes (q) was noted at 4 DPI in the SN following infection with McRed when compared with aged matched controls (bottom right of panels). White dotted region delineates the substania nigra pars compacta (SN) (N = 3/group). ****p < 0.0001