OBJECTIVES: Direct challenge of cortical serotonergic (5-hydroxytryptamine, 5-HT) availability by tryptophan depletion test (TDT) was used to assess the hypothesized inverse relationship between central 5-HT function and loudness dependence of auditory evoked potentials (LDAEPs). Gender must be taken into particular account here, since there are gender differences in 5-HT brain synthesis, with women reacting more strongly to TDT. METHODS: In a double-blind, controlled cross-over study, 16 healthy females were ingested two highly concentrated amino acid mixtures with (+TRP) or without TRP (-TRP). While monitoring TRP levels and mood states, the AEP of different loudness stimuli were recorded, followed by dipole source analysis. RESULTS: Under the -TRP condition, free plasma TRP levels decreased by 81.10% (+/-5.14). Most of the loudness change rates of the relevant N1/P2 tangential dipole activities were significantly increased under -TRP, but calculated LDAEP did not differ significantly between treatments. LDAEP and states of mood were not correlated. CONCLUSIONS: Despite strong TRP depletion, the results did not reach sufficient evidence that LDAEP is a valid biological marker of central 5-HT activity in females when using TDT. This agrees with the literature and supports the view that LDAEP indicates predominantly biological vulnerability in predisposed individuals. (c) 2007 John Wiley & Sons, Ltd.
RCT Entities:
OBJECTIVES: Direct challenge of cortical serotonergic (5-hydroxytryptamine, 5-HT) availability by tryptophan depletion test (TDT) was used to assess the hypothesized inverse relationship between central 5-HT function and loudness dependence of auditory evoked potentials (LDAEPs). Gender must be taken into particular account here, since there are gender differences in 5-HT brain synthesis, with women reacting more strongly to TDT. METHODS: In a double-blind, controlled cross-over study, 16 healthy females were ingested two highly concentrated amino acid mixtures with (+TRP) or without TRP (-TRP). While monitoring TRP levels and mood states, the AEP of different loudness stimuli were recorded, followed by dipole source analysis. RESULTS: Under the -TRP condition, free plasma TRP levels decreased by 81.10% (+/-5.14). Most of the loudness change rates of the relevant N1/P2 tangential dipole activities were significantly increased under -TRP, but calculated LDAEP did not differ significantly between treatments. LDAEP and states of mood were not correlated. CONCLUSIONS: Despite strong TRP depletion, the results did not reach sufficient evidence that LDAEP is a valid biological marker of central 5-HT activity in females when using TDT. This agrees with the literature and supports the view that LDAEP indicates predominantly biological vulnerability in predisposed individuals. (c) 2007 John Wiley & Sons, Ltd.
Authors: I Hui Lee; Yen Kuang Yang; Po See Chen; Hui Chun Huang; Tzung Lieh Yeh; Ru-Band Lu; Nan-Tsing Chiu; Wei Jen Yao; Shih-Hsien Lin Journal: Psychopharmacology (Berl) Date: 2010-11-12 Impact factor: 4.530
Authors: Irene Neuner; Wolfram Kawohl; Jorge Arrubla; Tracy Warbrick; Konrad Hitz; Christine Wyss; Frank Boers; N Jon Shah Journal: PLoS One Date: 2014-10-03 Impact factor: 3.240