Early Experimental Influences on Serotonin Pathways during Brain Development
In an attempt to gain information about the early influence of nutritional changes on the development of a specific neuronal system, we took advantage of the fact that an essential nutrient, namely L-Tryptophan (L-Trp), is the precursor molecule in the synthesis of a brain neurotransmitter, serotonin (5-hydroxytryptamine, 5-HT). Early experimental changes in the availability of such nutrient like protein-calorie malnutrition represented a useful experimental approach. It was also known, that L-Trp administration to adult rats induced an increase in brain 5-HT (1,2). The effect of L-Trp supplementation during the gestational period on the 5-HT biosynthetic pathway in the fetal brain was also tested. Both approaches, a defect of nutrients like early malnutrition and an excess of the precursor molecule, gave us interesting information about their early effects on the development of the brain serotonin system. Another experimental approach we used was the early administration of specific neurotoxics for serotonin neurons. So, we examined the effect of neonatal administration of 5,7-dihydroxytryptamine (5,7-DHT) and the developmental pattern of serotonin molecular markers during postnatal development. This approach gave us valuable information on the role of this neurotransmitter in determining the development of specific (3H) 5-HT binding sites.
KeywordsFetal Brain Developmental Pattern Precursor Molecule Postnatal Development Serotonin Synthesis
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