TITLE:
Functional Change of Brain Serotonergic Activity and Free Tryptophan in the Plasma of Depressed Women
AUTHORS:
Felipe Vázquez-Estupiñan, Rocío Herrera-Márquez, José Antonio Mondragón-Herrera, Guillermina Lara-Pérez, Gabriel Manjarrez-Gutiérrez
KEYWORDS:
Depression, Auditory-Evoked Potential (N1/P2) Component, Brain, Serotonin, L-Tryptophan
JOURNAL NAME:
Open Journal of Depression,
Vol.8 No.1,
January
17,
2019
ABSTRACT: The main objective was to show the decrement of serotoninergic brain activity in depressed women, through the analyses of the slope amplitude of N1/P2 components of the auditory-evoked potentials (AEP), and the measurement of the L-tryptophan free fraction in plasma (FFT). This cross-sectional study was carried out in 60 women, 30 depressed and 30 normal controls. Both groups were measured FFT, glucose, and neutral amino acids (NAA) levels; besides performing AEP to analyses the N1/P2 slope amplitude. It was found a lengthening in the slope amplitude of N1/P2 components of AEP in the group of depressed women, and despite that the level of FFT was low, there were no changes between bound fraction and the total L-Trp. The former suggests a decrease in serotonergic brain activity in the group of depressed women. Otherwise, since the auditory cortex response to sound is regulated by serotonergic innervation, it was expected a change in the behavior of AEP in the group of depressed patients. Thus, the slope amplitude of N1/P2 components of the AEP and the measurement of FFT have proved to be a good clinical indicators of the serotonergic neurotransmission state in the brain of depressed patients, and in another clinical conditions where brain serotonin is involved.