A, A representative RPA of total RNA (5 μg/lane) from saline- and cocaine-treated day 60 fetal monkey brain tissues illustrating the levels of PPE mRNA detected in the different brain regions of individual animals. UP, undigested probe; DP, digested probe; S, saline-treated; C, cocaine-treated.A1–A6 represent defined brain regions (see Materials and Methods). B, Linear regression analysis of the optical densities of the PPE mRNA sense standard curve revealedr = 0.995. C, Distribution and quantitative analysis of PPE mRNA in brain tissue obtained from saline-treated and cocaine-treated fetal macaques (n = 3 each). Densitometric scannings were normalized to cyclophilin mRNA and quantified from each sense mRNA standard curve. PPE mRNA was significantly increased in A1 (FC/ST) in cocaine-treated animals (*p < 0.05; paired two-tailed Student’st test).