On PD26-30, rats were deeply anesthetized and transcardially perfused with 0.9% saline. Brains were removed and transferred in Golgi-Cox solution in which they were left, in the dark, for three weeks. After which, they were transferred into 30% sucrose in saline. Two hundred micrometer coronal sections were cut through the entire extent of the PFC and collected in order on gelatinized slides. Slides were then processed as described previously (Gibb and Kolb, 1998; Whitcher & Klintsova, 2008).
