Postnatal development of the distribution of nitric oxide-producing neurons in the rat corpus callosum.

•NADPH-d-Hi was used to study the postnatal development of NO-producing neurons in the rat cc.•Intracallosal NADPH-d+Ns were detected at P0, their number increased between P0-P5.•Between P5-P10 number of NADPH-d+Ns declined and remained almost constant until P30.•Size increased during the first postnatal month, from 68 μ m2 (P0) to 249 μ m2 (P30).•Distribution of intracallosal NADPH-d+Ns changes with age.