A, Northern analysis reveals a distinct band for SGK1 mRNA in mouse ventral mesencephalon (VM). A band is also observed in the striatum (ST). SGK3 mRNA expression is also identified in the ventral mesencephalon, but not in the striatum. At a cellular level (right panels) SGK1 mRNA expression is identified by in situ hybridization in the SNpc, exclusively in neurons. The neurons bounded by the rectangle are shown at higher magnification in the inset. An adjacent section in the right panel hybridized with a sense probe (SGK1(S)) reveals an absence of signal. B, Immunoperoxidase staining for SGK protein reveals widespread expression in the ventral mesencephalon, including in the SNpc, (outlined by the dotted line). Double immunofluorescence staining for tyrosine hydroxylase (TH) (green) in SNpc dopaminergic neurons and SGK protein (red) reveals expression in the majority of these neurons, mainly in the nucleus, as shown in the inset.