Brain 5-HT function in bipolar affective disorder

2000 ◽  
Vol 12 (3) ◽  
pp. 91-95
Author(s):  
A.H. Young ◽  
J.H. Hughes ◽  
C.H. Ashton
Keyword(s):  
Bipolar Disorder ◽  
Power Spectrum ◽  
Evoked Potentials ◽  
Auditory Evoked Potentials ◽  
Auditory Evoked Potential ◽  
Brain Serotonin ◽  
Acute Tryptophan Depletion ◽  
Tryptophan Depletion ◽  
Eeg Activity ◽  
Bipolar Patients

ABSTRACTBackground: Previous studies suggest that brain serotonin neurotransmission may mediate the actions of lithium carbonate. Acute tryptophan depletion (ATD) reduces brain serotonin and allows the study of this neurotransmitter in patient groups. Serotonin modulates electroencephalographic (EEG) activity, which is abnormal in bipolar disorder, and EEG abnormalities persist in euthymic bipolar patients. The EEG may therefore be a sensitive marker of 5-HT function in bipolar disorder.Aims: This study examined the effects of ATD on mood, suicidal ideation and EEG activity in bipolar patients who were symptomatically stable on lithium.Methods: 19 subjects satisfying DSM-IV criteria for bipolar I disorder participated in a within-subject, double-blind, placebo-controlled random-order crossover study. Following acute tryptophan depletion (induced by a 100g amino acid drink following an overnight fast) symptoms were evaluated, quantitative power spectrum brain mapping and measurement of auditory evoked potentials were carried out.Results: ATD produced a significant fall in the amplitude of N1P2 and P300 components of the auditory evoked potential, but no significant changes in the power spectrum. There was an 83% reduction in plasma tryptophan (p<0.05, paired t-test) after the depleting but not the control drink. No significant changes in mood or suicidally scores were recorded after ATD.Conclusions: ATD attenuates auditory evoked potentials in bipolar disorder but does not reverse lithium's effects on mood and suicidally in bipolar disorder.

Acute tryptophan depletion in bipolar disorders; literature review and directives for further research

2000 ◽  
Vol 12 (3) ◽  
pp. 69-72 ◽  
Author(s):  
S. Sobczak ◽  
A. Honig ◽  
W.J. Riedel
Keyword(s):  
Bipolar Disorder ◽  
Literature Review ◽  
Affective Disorders ◽  
Bipolar Disorders ◽  
Acute Tryptophan Depletion ◽  
Tryptophan Depletion ◽  
Research Protocol ◽  
Methodological Procedures ◽  
Bipolar Patients ◽  
Methodological Aspects

ABSTRACTSerotonin (5-HT) has been implicated in the pathophysiology of bipolar disorders. Acute tryptophan depletion (ATD), which decreases serotonergic turnover, is an established paradigm to study serotonergic vulnerability in affective disorders. Literature on the application of ATD as a research tool in bipolar patients is limited to three studies, which revealed inconsistent results on mood modification. These inconsistencies may be attributed to differences in methodological procedures and / or characteristics of included patients. Patient selection, methodological aspects and procedures of these studies are critically considered and recommendations given. A research protocol to test the 5-HT vulnerability in bipolar disorder is proposed.

scholarly journals Effects of acute tryptophan depletion on mood and suicidal ideation in bipolar patients symptomatically stable on lithium

2000 ◽  
Vol 177 (5) ◽  
pp. 447-451 ◽  
Author(s):  
J. H. Hughes ◽  
F. Dunne ◽  
A. H. Young
Keyword(s):  
Suicidal Ideation ◽  
Random Order ◽  
Lithium Carbonate ◽  
Brain Serotonin ◽  
Acute Tryptophan Depletion ◽  
Tryptophan Depletion ◽  
Double Blind ◽  
Plasma Tryptophan ◽  
Patient Groups ◽  
Bipolar Patients

BackgroundPrevious studies suggest that brain serotonin neurotransmission may mediate the actions of lithium carbonate. Acute tryptophan depletion reduces brain serotonin and allows the study of this neurotransmitter in patient groups.AimsTo examine the effects of acute tryptophan depletion on mood and suicidal ideation in bipolar patients who were symptomatically stable on lithium.MethodNineteen subjects satisfying DSM–IV criteria for bipolar I disorder participated in a within-subject, double-blind, placebo-controlled random-order crossover study. Symptoms were evaluated following acute tryptophan depletion, which was induced by a 100 g amino acid drink following an overnight fast.ResultsPlasma tryptophan fell significantly after the depleting drink, but not after the control drink (P < 0.05, paired t-test, mean reduction 83%). No significant changes in mood or suicidality scores were recorded after acute tryptophan depletion.ConclusionsAcute tryptophan depletion does not reverse lithium's effects on mood and suicidality in bipolar disorder.

Cognition following acute tryptophan depletion: difference between first-degree relatives of bipolar disorder patients and matched healthy control volunteers

2002 ◽  
Vol 32 (3) ◽  
pp. 503-515 ◽  
Author(s):  
S. SOBCZAK ◽  
W. J. RIEDEL ◽  
I. BOOIJ ◽  
M. AAN HET ROT ◽  
N. E. P. DEUTZ ◽  
...  
Keyword(s):  
Bipolar Disorder ◽  
Information Processing ◽  
Memory Performance ◽  
Acute Tryptophan Depletion ◽  
Tryptophan Depletion ◽  
Type I ◽  
Term Memory ◽  
First Degree Relatives ◽  
Speed Of Information Processing ◽  
Bipolar Patients

Background. Serotonergic circuits have been proposed to mediate cognitive processes, particularly learning and memory. Cognitive impairment is often seen in bipolar disorders in relation to a possible lowered serotonergic turnover.Methods. We investigated the effects of acute tryptophan depletion (ATD) on cognitive performance in healthy first-degree relatives of bipolar patients (FH) (N = 30) and matched controls (N = 15) in a placebo-controlled, double-blind cross-over design. Performance on planning, memory and attention tasks were assessed at baseline and 5 h after ATD.Results. Following ATD, speed of information processing on the planning task was impaired in the FH group but not in the control group. FH subjects with a bipolar disorder type I relative (FH I) showed impairments in planning and memory, independent of ATD. In all subjects, ATD impaired long-term memory performance and speed of information processing. ATD did not affect short-term memory and focused and divided attention.Conclusions. The results suggest serotonergic vulnerability affecting frontal lobe areas in FH subjects, indicated by impaired planning. Biological vulnerability in FH I subjects is reflected in impaired planning and memory performance. In conclusion, the cognitive dysfunctions in FH subjects indicate an endophenotype constituting a possible biological marker in bipolar psychopathology. Serotonin appears to be involved in speed of information processing, verbal and visual memory and learning processes.

scholarly journals Effects of Acute Tryptophan Depletion on Brain Serotonin Function and Concentrations of Dopamine and Norepinephrine in C57BL/6J and BALB/cJ Mice

PLoS ONE ◽  
2012 ◽  
Vol 7 (5) ◽  
pp. e35916 ◽  
Author(s):  
Caroline Sarah Biskup ◽  
Cristina L. Sánchez ◽  
Andrew Arrant ◽  
Amanda E. D. Van Swearingen ◽  
Cynthia Kuhn ◽  
...  
Keyword(s):  
Brain Serotonin ◽  
Acute Tryptophan Depletion ◽  
Tryptophan Depletion

scholarly journals A Structured ICA-based Process for Removing Auditory Evoked Potentials Reveals TMS-evoked Potentials and TMS-modulated Oscillations

2021 ◽  
Author(s):  
Jessica M. Ross ◽  
Recep A. Ozdemir ◽  
Shu Jing Lian ◽  
Peter J. Fried ◽  
Eva M. Schmitt ◽  
...  
Keyword(s):  
Evoked Potentials ◽  
Time Course ◽  
Auditory Evoked Potentials ◽  
Time Window ◽  
Auditory Evoked Potential ◽  
Cosine Similarity ◽  
Similarity Analysis ◽  
Stimulation Site ◽  
Individual Subject ◽  
Site Specific

Abstract Background: Transcranial magnetic stimulation (TMS)-evoked potentials (TEPs), recorded using electroencephalography (EEG), reflect a combination of TMS-induced cortical activity and multi-sensory responses to TMS. The auditory evoked potential (AEP) is a high-amplitude sensory potential—evoked by the “click” sound produced by every TMS pulse—that can dominate the TEP and obscure observation of other neural components. The AEP is peripherally evoked and therefore should not be stimulation site specificObjectives/Methods: We address the problem of disentangling the peripherally evoked AEP of the TEP from components evoked by cortical stimulation and ask whether removal of AEP enables more accurate isolation of TEP. We hypothesized that isolation of the AEP using Independent Components Analysis (ICA) would reveal features that are stimulation site specific and unique individual features. In order to improve the effectiveness of ICA for removal of AEP from the TEP, and thus more clearly separate the transcranial-evoked and non-specific TMS-modulated potentials, we merged sham and active TMS datasets representing multiple stimulation conditions, removed the resulting AEP component, and evaluated performance across different sham protocols and clinical populations using reduction in Global and Local Mean Field Potentials (GMFA/LMFA) and cosine similarity analysis.Results: We show that removing AEPs significantly reduced GMFA and LMFA in the post-stimulation TEP (14 to 400 ms), driven by time windows consistent with the N100 and P200 temporal characteristics of AEPs. Cosine similarity analysis supports that removing AEPs reduces TEP similarity between subjects and reduces TEP similarity between stimulation conditions. Similarity is reduced most in a mid-latency window consistent with the N100 time-course, but nevertheless remains high in this time window. Residual TEP in this window has a time-course and topography unique from AEPs, which follow-up analyses suggest could be a modulation in the alpha band that is not stimulation site specific but is unique to individual subject.Conclusion(s): We show, using two datasets and two implementations of sham, evidence in cortical topography, TEP time-course, GMFA/LMFA and cosine similarity analyses that this procedure is effective and conservative in removing the AEP from TEP, and thereby reveals better defined TMS-evoked activity. We show TEP remaining in early, mid and late latencies. The early response is site and subject specific. Later responses are consistent with TMS-modulated alpha activity that is not site specific but is unique to the individual. TEP remaining after removal of AEP is unique and can provide insight into TMS-evoked potentials and other modulated oscillatory dynamics.

scholarly journals Parameters for Applying the Brainstem Auditory Evoked Potential with Speech Stimulus: Systematic Review

2017 ◽  
Vol 22 (04) ◽  
pp. 460-468 ◽  
Author(s):  
Luísa Gabriel ◽  
Luíza Vernier ◽  
Maria Ferreira ◽  
Adriana Silveira ◽  
Márcia Machado
Keyword(s):  
Systematic Review ◽  
Evoked Potentials ◽  
Brain Stem ◽  
Auditory Evoked Potentials ◽  
Evoked Potential ◽  
Sampling Rate ◽  
Presentation Rate ◽  
Auditory Evoked Potential ◽  
Speech Stimulus ◽  
Brainstem Auditory Evoked Potential

Introduction Studies using the Brainstem Auditory Evoked Potential with speech stimulus are increasing in Brazil, and there are divergences between the methodologies used for testing. Objectives To analyze the parameters used in the study of the Brainstem Auditory Evoked Potentials with speech stimulus. Data Synthesis The survey was performed using electronic databases. The search strategy was as follows: “Evoked potentials, auditory” OR “Brain stem” OR “Evoked potentials, auditory, brain stem” AND “Speech.” The survey was performed from June to July of 2016. The criteria used for including articles in this study were: being written in Portuguese, English or Spanish; presenting the description of the testing parameters and the description of the sample. In the databases selected, 2,384 articles were found, and 43 articles met all of the inclusion criteria. The predominance of the following parameters was observed to achieve the potential during study: stimulation with the syllable /da/; monaural presentation with greater use of the right ear; intensity of 80 dB SPL; vertical placement of electrodes; use of in-ear headphones; patient seated, distracted in awake state; alternating polarity; use of speech synthesizer software for the elaboration of stimuli; presentation rate of 10.9/s; and sampling rate of 20 kHz. Conclusions The theme addressed in this systematic review is relatively recent. However, the results are significant enough to encourage the use of the procedure in clinical practice and advise clinicians about the most used procedures in each parameter.

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