Examining Serotonin Function: A Modified Technique for Rapid Tryptophan Depletion

Krahn, Lois E.; Lu, Peter Y.; Klee, George G.; Delgado, Pedro R.; Lin, S.C.; Zimmermann, Ralf

doi:10.1016/0893-133x(95)00273-g

Cited by 29 publications

(28 citation statements)

References 8 publications

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“…One potential solution would be to evaluate lower doses of the amino acid drink to improve palatability. A low-dose 25-g TϪ drink has been shown to produce a 50% suppression of the plasma Trp/LNAA ratio in men and women (Krahn et al 1996) compared with the 69% decrease of plasma total Trp in this current study. Whether smaller doses of these amino acid drinks would result in behavior changes remains to be determined.…”

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confidence: 43%

Laboratory-Measured Aggressive Behavior of Women Acute Tryptophan Depletion and Augmentation

Marsh

2002

Neuropsychopharmacology

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Plasma L -tryptophan (Trp) reductions have been related to aggression increases in men. Impairment of serotonin synthesis and neurotransmission is one explanation. Using repeated-measures, this Trp manipulation study measured laboratory-induced aggression in 12 women after Trp augmentation (T ϩ ), depletion (T Ϫ ), and food-restricted (fasting control) conditions. Participants were provoked with periodic subtraction of money from their task earnings by a (fictitious) partner. Aggression was defined as the number of point subtractions participants made from their fictitious partner. Participants completed five testing sessions under each condition. T ϩ decreased aggressive responses and T Ϫ increased aggressive responses. Post-hoc analyses showed changes in aggressive behavior were specific to women with higher fasting control plasma Trp, which is consistent with research demonstrating that men with higher levels of baseline Trp are more aggressive. These findings indicate that both T ϩ and T Ϫ can influence aggressive behavior and that certain subgroups of womenA number of psychobiological syndromes characterized by poor impulse control have been associated with low concentrations of the major serotonin (5-HT) metabolite 5-hydroxyindoleacetic acid (5-HIAA) in cerebrospinal fluid (CSF). Serotonin dysfunction has been correlated with impulsive and violent criminal behaviors (Brown et al. , 1982Lidberg et al. 1985;Limson et al., 1991;Virkkunen and Närvänen 1987;Virkkunen et al. 1994aVirkkunen et al. , 1994b, alcohol abuse and dependence (Badawy et al. 1995;Ballenger et al. 1979;Banki 1981;Borg et al. 1985;Moss 1987;Roy and Linnoila 1989), Gilles de la Tourette's syndrome (Butler et al. 1979;Cohen et al. 1978Cohen et al. , 1979, bulimia (Jimerson et al. 1990(Jimerson et al. , 1992, and suicide attempts (Asberg et al. 1976(Asberg et al. , 1986Banki and Arato 1983;López-Ibor et al. 1985), as well as with children institutionalized for aggressive behavior (Kruesi 1989;Kruesi et al. 1990Kruesi et al. , 1992.Direct experimental manipulation of 5-HT levels and the measurement of resultant behavior have provided stronger evidence for the connection between central nervous system (CNS) 5-HT and impulsive/aggressive behaviors. Serotonin synthesis depends on the availability of the essential amino acid tryptophan (Trp). Thus, manipulation of 5-HT can be accomplished through increases or decreases in dietary Trp, which in turn increases or decreases plasma Trp and ultimately 5-HT in the CNS Gessa et al. 1974; Online publication: 9/14/01 at www.acnp.org/citations/ Npp091401176. N EUROPSYCHOPHARMACOLOGY 2002 -VOL . 26 , NO . 5 Tryptophan and Aggression 661 Young et al. 1989). This manipulation is postulated to affect brain 5-HT because 5-HT synthesis depends primarily on Trp availability (Fernstrom 1983 (Carpenter et al. 1998;Young and Gauthier 1981), rate reductions of 5-HT synthesis in the human brain (Nishizawa et al. 1997), and blunted release of 5-HT from serotonergic neurons in vivo (Stancampiano et al. 1997). As a res...

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confidence: 43%

Laboratory-Measured Aggressive Behavior of Women Acute Tryptophan Depletion and Augmentation

Marsh

2002

Neuropsychopharmacology

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“…Therefore, the biosynthesis of melatonin depends on the availability of tryptophan. It is well documented that during cases of acute tryptophan depletion, there is a significant decrease in plasma levels of melatonin [30] and those of urinary 6-hydroxy melatonin sulfate [31,32] . Thus, tryptophan deficiency is due to sleep disorders associated with a lack of melatonin [33,34] .…”

Section: E Use Of Tryptophan and Vitamin B6 As Elements For Increasimentioning

confidence: 99%

Comparative Study between the use of Melatonin and A Solution with Melatonin, Tryptophan, and Vitamin B6 as an Inducer of Spontaneous Sleep in Children During an Auditory Response Test: An Alternative to Commonly Used Sedative Drugs

Volpe¹,

Lucia²,

Pirozzi³

et al. 2017

Int Adv Otol

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MATERIALS and METHODS:In total, 748 children aged between 12 and 48 months were included in the study and divided into three groups: A: placebo (n=235), B: melatonin (n=246), and C: melatonin, tryptophan, and vitamin B6 (n=267). RESULTS:In groups B and C, in addition to physiological awakening, we observed a significant reduction in the number of repeated analyses as well as drug regimen usage. CONCLUSION:This study confirms the strategic role of melatonin as an inducer of spontaneous sleep. However, above all, it suggests that the administration of a solution containing melatonin, tryptophan, and vitamin B6 significantly reduces the number of repeated ABR examinations as well as the percentage of repeated analysis performed using sedative drugs compared to both the control group and the melatonin-only group.

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“…3,4 Two control procedures are commonly used: one in which a small amount of Trp is added to the AA mixture, and one in which 25 g instead of 100 g of AAs is consumed. 17 The latter procedure was used in the United States during the 1990s, when Trp was banned from the US market. The results are not the same: the first procedure leads to a rise in plasma Trp that can vary in size, whereas the latter procedure usually leads to modest reductions of plasma Trp.…”

Section: Acute Tryptophan Depletionmentioning

confidence: 99%

Monoamine depletion in psychiatric and healthy populations: review

2003

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A number of techniques temporarily lower the functioning of monoamines: acute tryptophan depletion (ATD), alpha-methyl-para-tyrosine (AMPT) and acute phenylalanine/tyrosine depletion (APTD). This paper reviews the results of monoamine depletion studies in humans for the period 1966 until December 2002. The evidence suggests that all three interventions are specific, in terms of their short-term effects on one or two neurotransmitter systems, rather than on brain protein metabolism in general. The AMPT procedure is somewhat less specific, affecting both the dopamine and norepinephrine systems. The behavioral effects of ATD and AMPT are remarkably similar. Neither procedure has an immediate effect on the symptoms of depressed patients; however, both induce transient depressive symptoms in some remitted depressed patients. The magnitude of the effects, response rate and quality of response are also comparable. APTD has not been studied in recovered major depressive patients. Despite the similarities, the effects are distinctive in that ATD affects a subgroup of recently remitted patients treated with serotonergic medications, whereas AMPT affects recently remitted patients treated with noradrenergic medications. The evidence also suggests that ATD and APTD affect different cognitive functions, in particular different memory systems. Few studies investigated cognitive effects of the procedures in patients. Patients who are in remission for longer may also be vulnerable to ATD and AMPT, but the relationship with prior treatment is much weaker. For these patients, individual vulnerability markers are the more important determinants of depressive response, making these techniques potentially useful models of vulnerability to depression. Molecular Psychiatry (2003) 8, 951-973.

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Examining Serotonin Function: A Modified Technique for Rapid Tryptophan Depletion

Cited by 29 publications

References 8 publications

Laboratory-Measured Aggressive Behavior of Women Acute Tryptophan Depletion and Augmentation

Laboratory-Measured Aggressive Behavior of Women Acute Tryptophan Depletion and Augmentation

Comparative Study between the use of Melatonin and A Solution with Melatonin, Tryptophan, and Vitamin B6 as an Inducer of Spontaneous Sleep in Children During an Auditory Response Test: An Alternative to Commonly Used Sedative Drugs

Monoamine depletion in psychiatric and healthy populations: review

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