Prenatal impairment of brain serotonergic transmission in infants.
OBJECTIVE
To evaluate whether the free fraction of L-tryptophan (L-Trp) and the N1/P2 component of the auditory evoked potentials (AEPs) are associated with impaired brain serotonin neurotransmission in infants with intrauterine growth restriction (IUGR).


METHODS
We measured free, bound, and total plasma L-Trp and recorded the N1/P2 component of AEP in a prospective, longitudinal, and comparative study comparing IUGR and control infants.


RESULTS
Plasma free L-Trp was increased and the amplitude of N1/P2 component was significantly decreased in IUGR relative to control infants. The free fraction of L-Trp and N1/P2 component had a negative association.


CONCLUSIONS
In newborns with IUGR, the changes in measured plasma free fraction of L-Trp and in the amplitude the N1/P2 component of the AEP suggest an inverse association between free L-Trp and components of the AEP. The changes observed in the free fraction of L-Trp and AEP may be causally associated with brain serotonergic activity in utero. In IUGR, epigenetic factors such as stress-induced disturbances in brain serotonin metabolism or serotonergic activity, identifiable by alterations in AEP, influence cerebral sensory cortex development and may be causally associated with serotonin-related disorders in adulthood.
Manjarrez
Gabriel
G
Laboratory of Developmental Neurochemistry, Specialties Hospital, XXI Century National Medical Center, Mexican Institute of Social Security, Av. Cuauhtémoc 330, Col. Doctores, CP 06720, Mexico City, Mexico. willisga@df1.telmex.net.mx
Cisneros
Ignacia
I
Herrera
Rocio
R
Vazquez
Felipe
F
Robles
Alejandro
A
Hernandez
Jorge
J
D000704:Analysis of Variance; D015415:Biomarkers; D002540:Cerebral Cortex / Q000196:embryology / Q000378:metabolism*; D005072:Evoked Potentials, Auditory; D005317:Fetal Growth Retardation / Q000503:physiopathology*; D006801:Humans; D007231:Infant, Newborn; D011446:Prospective Studies; D011930:Reaction Time; D012701:Serotonin / Q000378:metabolism*; D018709:Statistics, Nonparametric; D014364:Tryptophan / Q000097:blood*
D015415:Biomarkers; D012701:Serotonin; D014364:Tryptophan