Serotonin levels are abnormally elevated in the fetus of the monoamine oxidase-A-deficient transgenic mouse

Developmental changes in levels of serotonin, I-tryptophan and 5-hydroxyind ol acetic acid (5-HIAA) were measured by high pressure liquid chromatograph y (HPLC) in the forebrain, brainstem and cervical cord of fetal, neonatal a nd adult mice from the wild strain C3H and the transgenic strain Tg8, creat ed from the C3H line by the disruption of the gene encoding monoamine oxida se A. The results indicated that the absence of monoamine oxidase A activit y in Tg8 mice results in abnormally high 5-hydroxytryptamine (5-HT) levels in all the central nervous structures and at all the studied developmental ages. Since serotonin levels were 4-5 times larger in Tg8 than in C3H mice at gestational day 20, comparing the central network function at birth of C 3H and Tg8 neonates should shed some light on the role of serotonin in pren atal network maturation. (C) 1999 Elsevier Science Ireland Ltd. All rights reserved.