POSTNATAL-DEVELOPMENT OF NADPH-DIAPHORASE ACTIVITY IN THE SUPERIOR COLLICULUS AND THE VENTRAL LATERAL GENICULATE-NUCLEUS OF THE RAT

We have studied the postnatal development of dihydronicotinamide adeni ne dinucleotide phosphate diaphorase (NADPH-d) activity in the superio r colliculus (SC) and the ventral lateral geniculate nucleus (LGv) of the rat. We describe two different developmental patterns of NADPH-dia phorase activity. The first pattern, observed in the deep layers of th e SC, shows a transient activity during the first week which progressi vely decreases during the following two weeks. The second pattern is o bserved in the superficial layers of the SC and in the LGv. They becom e positive during the first week, their NADPH-d activity increases pro gressively during the second and third weeks, reaching the adult patte rn at the fourth week. On the whole, the developmental chronology of t he laminar distribution of NADPH-d in the SC displays an inside-out pa ttern. Our results suggest that NADPH-d activity may play different ro les at different stages of the developing nervous system.