Tyrosine administration prevents hypoxia-induced decrements in learning and memory

Shukitt‐Hale, Barbara; Stillman, Michael J.; Lieberman, Harris R.

doi:10.1016/0031-9384(95)02107-8

Cited by 42 publications

(12 citation statements)

References 19 publications

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“…Injury to the brain through loss of oxygen triggers memory loss and causes learning deficiencies (Shukitt-Hale et al, 1996) including anterograde amnesia (Beatty et al, 1987). Importantly, acute hypoxia activates the neuroimmune system especially its IL-1 arm (Johnson et al, 2007).…”

Section: Introductionmentioning

confidence: 99%

Hypoxia/Reoxygenation Impairs Memory Formation via Adenosine-Dependent Activation of Caspase 1

Chiu

Chatterjee²,

Darmody³

et al. 2012

J. Neurosci.

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After hypoxia, a critical adverse outcome is the inability to create new memories. How anterograde amnesia develops or resolves remains elusive, but a link to brain-based IL-1 is suggested due to the vital role of IL-1 in both learning and brain injury. We examined memory formation in mice exposed to acute hypoxia. After reoxygenation, memory recall recovered faster than memory formationimpacting novel object recognition and cued fear conditioning but not spatially cued Y-maze performance. The ability of mice to form new memories after hypoxia/reoxygenation was accelerated in IL-1 receptor 1 knockout (IL-1R1 KO) mice, in mice receiving IL-1 receptor antagonist (IL-1RA) and in mice given the caspase 1 inhibitor, Ac-YVAD-CMK. Mechanistically, hypoxia/reoxygenation more than doubled caspase 1 activity in the brain which was localized to the amygdala compared to the hippocampus. This reoxygenation-dependent activation of caspase 1 was prevented by broad-spectrum adenosine receptor (AR) antagonism with caffeine and by targeted A1/A2A AR antagonism with 8-cyclopentyl-1, 3-dipropylxanthine + 3, 7-dimethyl-1-propargylxanthine. Additionally, perfusion of adenosine activated caspase 1 in the brain while caffeine blocked this action by adenosine. Finally, resolution of anterograde amnesia was improved by both caffeine and by targeted A1/A2A AR antagonism. These findings indicate that amygdala-based anterograde amnesia after hypoxia/reoxygenation is sustained by IL-1β generated through adenosine-dependent activation of caspase 1 after reoxygenation.

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Section: Introductionmentioning

confidence: 99%

Hypoxia/Reoxygenation Impairs Memory Formation via Adenosine-Dependent Activation of Caspase 1

Chiu

Chatterjee²,

Darmody³

et al. 2012

J. Neurosci.

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“…Acute tyrosine depletions in healthy adult humans have been associated with increases in arousal, depression, and anxiety (McCann et al, 1995), as well as impaired cognitive function (McCann et al, 1992) and decreased responses to the rewarding effects of alcohol (Rammsayer & Vogel, 1995). Alternatively, under stressful conditions, tyrosine administration improves learning and working memory performance in animals (Ahlers, Salander, Shurtleff, & Thomas, 1992;Shukitt-Hale, Stillman, & Lieberman, 1996;Shurtleff, Thomas, Ahlers, & Schrot, 1993) and in humans (Deijen & Orlebeke, 1994;Shurtleff, Thomas, & Schrot, 1994).…”

Section: Introductionmentioning

confidence: 99%

Associations between Phenylalanine‐to‐Tyrosine Ratios and Performance on Tests of Neuropsychological Function in Adolescents Treated Early and Continuously for Phenylketonuria

2001

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Phenylketonuria (PKU) is a genetic disorder characterized by hyperphenylalaninemia. Treatment involves dietary phenylalanine restriction to prevent mental retardation. Because phenylalanine is involved in tyrosine synthesis and tyrosine is a catecholamine precursor, low tyrosine may lead to brain dopamine deficiencies. Because dopamine is involved in the modulation of prefrontally orchestrated executive functions, deficiencies may lead to executive impairments. Despite treatment, impairments in executive cognitive functions have been reported in young children with PKU. Outcome beyond middle childhood has not been extensively investigated. In this study, PKU-affected adolescents (N = 18) with normal-range IQ scores completed neuropsychological tests, and their performance was compared with unaffected peers (N = 16) and chronically ill controls (N = 17). Results demonstrated that the overall performance of the PKU group did not differ from that of the other two groups, but that performance of the PKU proband was associated with phenylalanine and tyrosine levels, and most strongly with phenylalanine-to-tyrosine ratios at several points in development. These findings provide a preliminary test of the dopamine hypothesis of PKU as it applies to adolescents and young adults.

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“…Additional studies have confirmed and extended these findings (49,87). Rat studies have confirmed these results and also shown that tyrosine treatment reverses working memory escape latency decrements and alleviates hypoxiainduced retardation of learning (50,85).…”

Section: Benefits Of Tyrosine Supplementationmentioning

confidence: 74%

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 administration prevents hypoxia-induced decrements in learning and memory

Cited by 42 publications

References 19 publications

Hypoxia/Reoxygenation Impairs Memory Formation via Adenosine-Dependent Activation of Caspase 1

Hypoxia/Reoxygenation Impairs Memory Formation via Adenosine-Dependent Activation of Caspase 1

Associations between Phenylalanine‐to‐Tyrosine Ratios and Performance on Tests of Neuropsychological Function in Adolescents Treated Early and Continuously for Phenylketonuria

Supplemental tyrosine and vigilance performance in a normoxic hypobaric environment

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