All panels are coronal sections through the forebrain. (A-B) At E18.5, RARβ mRNA is greatly reduced in the striatum (LGE) of an Raldh3-/- (R3-/) embryo particularly in the ventral region including the nucleus accumbens. (C-D) DARPP-32 immunohistochemistry at E18.5 demonstrating no significant difference between wild-type and Raldh3-/- forebrain. ac, anterior commissure; cx, cortex; LGE, lateral ganglionic eminence; na, nucleus accumbens; str, striatum.