Ontogeny of the levels of serotonin in various parts of the brain in severely protein malnourished rats.

We have previously reported that irreversible central and peripheral chemical changes and irreversible changes in spontaneous activity of single neurons in the frontal cortex are seen in adult rats who were born to mothers fed an 8% isocaloric casein diet 5 weeks before mating and during gestation, who were cross-fostered at birth by control (25% casein diet fed) dams and who showed a normal growth curve. Thus, in the rat, a normal growth curve does not necessarily mean a normal development. We now report similar irreversible, albeit larger, changes in small-for-gestational-age (SGA) rats born to mothers fed a 6% isocaloric diet, nursed by 6% casein fed dams and who showed an abnormal growth curve. The regional ontogeny of serotonin, tryptophan and 5-HIAA in the brain and plasma levels of tryptophan, protein, albumin and NEFA are reported. Thus, similar changes were observed in animals with a normal growth curve and in animals with a very markedly decreased growth curve resembling marasmus in humans.