Saturation curves of [3H]compound D binding sites in the P7 (n = 3) and adult (n = 3) rat brains. The estimated values (mean ± SEM) of Bmax and Kd for different brain regions are, respectively, as follows: P7 hippocampal formation, 612 ± 54 fmol/mg and 3.1 ± 1.5 nm; P7 cerebellum, 558 ± 57 fmol/mg and 4.2 ± 2.1 nm; P7 frontoparietal cortex, 421 ± 28 fmol/mg and 3.2 ± 1.2 nm; adult cerebellar cortex, 327 ± 29 fmol/mg and 3.9 ± 1.8 nm; adult hippocampal CA3 region, 320 ± 32 fmol/mg and 3.2 ± 1.7 nm; and adult frontoparietal cortex, 304 ± 21 fmol/mg and 2.8 ± 1.1 nm.