Treatment with tyrosine, a neurotransmitter precursor, reduces environmental stress in humans

Banderet, Louis E.; Lieberman, Harris R.

doi:10.1016/0361-9230(89)90096-8

Cited by 185 publications

(103 citation statements)

References 13 publications

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“…Creatine, a nutrient that improves energy availability, also appears to benefit overall cognitive performance (Rae et al 2003) and reduce mental fatigue (Watanabe et al 2002;McMorris et al 2006). Besides being an energy source, food can contribute to cognition by providing amino acids needed in the production of neurotransmitters, which is particularly important during periods of stress or sustained concentration (Banderet and Lieberman 1989;Deijen et al 1999;Lieberman 2003). There is also evidence that micronutrient supplementation increases nonverbal intelligence in some children.…”

Section: Drugsmentioning

confidence: 99%

Cognitive Enhancement: Methods, Ethics, Regulatory Challenges

2009

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Cognitive enhancement takes many and diverse forms. Various methods of cognitive enhancement have implications for the near future. At the same time, these technologies raise a range of ethical issues. For example, they interact with notions of authenticity, the good life, and the role of medicine in our lives. Present and anticipated methods for cognitive enhancement also create challenges for public policy and regulation.

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Section: Drugsmentioning

confidence: 99%

Cognitive Enhancement: Methods, Ethics, Regulatory Challenges

2009

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“…Plasma levels have been shown to remain elevated above baseline values for over 4.5 hours. Banderet and Lieberman reported human plasma tyrosine baseline values of 42 ±3.3 nmoles/ml and following administration of 100 mg/kg of supplemental tyrosine, plasma levels were 108 ± 5.1 nmoles/ml after 150 minutes and still elevated at 98.6 ± 6.3 nmoles/ml after 265 minutes (6). While plasma levels increase with increasing amounts of dietary protein, CSF levels will rise slightly until increased competition from other large neutral amino acids inhibits tyrosine transport across the blood-brain barrier.…”

Section: Dietary Requirementsmentioning

confidence: 98%

“…Mammalian brains synthesize the catecholamines from the amino acid precursor tyrosine, a large neutral amino acid found in dietary proteins (6,32,55,82). Figure 1 shows the biosynthesis pathway.…”

Section: Stress and Catecholamine Synthesismentioning

confidence: 99%

“…The turnover rates vary from region to region, and when individuals are placed in a highly stressful situation or environment, catecholamine turnover increases and often synthesis does not keep pace with neurotransmitter release (6,70,83). One reason for this is because of the stress-induced elevation of glucocorticoids, which act to regulate "the synthesis and degradation of enzymes involved in the formation of catecholamines" (92).…”

Section: Stress and Catecholamine Synthesismentioning

confidence: 99%

“…It is not known how effective tyrosine might be in extremely sleep-deprived and fatigued individuals. One promising aspect of the use of tyrosine to combat stress is that since it is readily found in common foods, there are no side effects to its use, and it is unlikely to have any longterm toxicity (6,51,62,83). The primary reason for this is because, as a food constituent, tyrosine does not "interact directly with the synaptic macromolecules or accumulate in vivo" (47).…”

Section: Stress and Catecholamine Synthesismentioning

confidence: 99%

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Supplemental tyrosine and vigilance performance in a normoxic hypobaric environment

Maresh¹

2001

PsycEXTRA Dataset

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The public re(jortii.g burden for this collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing the collection of information. Send comments regarding this burden estimate or any other aspect of this collection o; rnfo'rnation. including suggestions for reducing the burden, to Department of Defense, Washington Headquarters Services, Directorate for Information Exposure to stress results in a decrease in mental performance resulting from a depletion of catecholamines. This decrease can result in an increase in error rates, decreased decision making ability, mental confusion, and an overall decrease in cognitive performance. Previous studies have shown that supplemental tyrosine prevents the normal decrease due to stress.Tyrosine works by increasing the catecholamine precursor.Nine subjects were exposed to a 3-hour protocol for 4 different exposures. During each exposure, the following Stressors were used: 1) hypobaric environment (for two of the four exposures); 2) immobilization; 3) prolonged inactivity; 4) behavioral and psychophysiological testing; 5) cool temperatures and low humidity; and 6) 71 dB(A) chamber environment. Subjects completed computerized vigilance and cognitive tests and a mood questionnaire, each separated by a period of inactivity. Prior to exposure, subjects ingested either 100 mg/kg body weight of a placebo or tyrosine.Supplemental tyrosine improved response time in all of the tests where it was recorded, with all except one being significant. Motor function and overall mood also significantly improved with the use of tyrosine. As expected, no measurement showed a significant improvement in performance with supplemental oxygen alone. The use of supplemental tyrosine did not significantly improve cognitive performance. Results of the contrast sensitivity taskswere not as conclusive and no improvement was found in visual temporal acuity. and physical performance. The less control the individual has over these stresses, the greater the decrement. The decrease in performance, particularly mental performance, results from a depletion of catecholamines within the brain. This decrease, especially in norepinephrine, leads to alterations in normal brain function and an increase in error rates, decreased decision making ability, mental confusion, and an overall decrease in cognitive performance. All of these are compounded the longer the individual is unable to remove the stress. Previous studies involving rats and humans have shown that supplemental tyrosine (levels above normal dietary intake) prevent the normal decrease in performance in stressed individuals. Tyrosine, the initial precursor in catecholamine synthesis, works by increasing the availability of the precursor and thereby slowing the rate of norepinephrine depletion.Nine healthy subjects from the Colorado State University community were exposed to a 3-hour protocol that w...

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Tyrosine enhances behavioral and mesocorticolimbic dopaminergic responses to aversive conditioning

Morrow

Elsworth

Roth

1996

Synapse

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Tyrosine is a precursor in the biosynthesis of catecholamines and, when administered systemically, has been shown to enhance the in vivo rate of tyrosine hydroxylation in the medial prefrontal cortex. Additionally, exogenous tyrosine has been demonstrated to enhance the pharmacologically‐induced increase in dopamine metabolism seen following administration of haloperidol or the anxiogenic B‐carboline, FG‐7142. In this report, we examine the effect of a physiologically relevant dose of tyrosine (25 mg/kg) on biochemical and behavioral consequences of aversive conditioning. Rats were conditioned to fear a tone by pairing it with footshock, so that when challenged with the tone alone, rats responded with immobility, defecation, and elevated dopamine metabolism in the medial prefrontal cortex and nucleus accumbens. When tyrosine was administered on the test day (tones alone), the rats displayed an even greater elevation of dopamine metabolism in the nucleus accumbens and prolonged immobility to the tone, compared to the saline/conditioned controls. Tyrosine did not alter mobility or dopamine utilization in the nucleus accumbens in nonconditioned controls. However, dopamine metabolism in the medial prefrontal cortex of nonconditioned rats treated with tyrosine was increased to levels similar to those in the conditioned groups. This may be accounted for by handling and by exposure to an unfamiliar environment necessary for nonconditioned controls. We conclude that exogenous tyrosine is able to 1) elevate stress‐induced dopamine metabolism in the nucleus accumbens, 2) alter dopamine utilization in the medial prefrontal cortex of handled, nonconditioned controls, and 3) enhance fear‐induced immobilization. These data suggest a role for dietary tyrosine in biochemical and behavioral responses to aversive stimuli. © 1996 Wiley‐Liss, Inc.

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Treatment with tyrosine, a neurotransmitter precursor, reduces environmental stress in humans

Cited by 185 publications

References 13 publications

Cognitive Enhancement: Methods, Ethics, Regulatory Challenges

Cognitive Enhancement: Methods, Ethics, Regulatory Challenges

Supplemental tyrosine and vigilance performance in a normoxic hypobaric environment

Tyrosine enhances behavioral and mesocorticolimbic dopaminergic responses to aversive conditioning

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