Neuro-Cognitive Effects of Acute Tyrosine Administration on Reactive and Proactive Response Inhibition in Healthy Older Adults

source extracted confidence: high 2026-04-09
#aged #aging #anticipation-psychological #double-blind-method #executive-function

Neuro-Cognitive Effects of Acute Tyrosine Administration on Reactive and Proactive Response Inhibition in Healthy Older Adults

Bloemendaal et al., 2018 | eNeuro | Rct

Citation

Bloemendaal Mirjam, Froböse Monja Isabel, ... Aarts Esther. Neuro-Cognitive Effects of Acute Tyrosine Administration on Reactive and Proactive Response Inhibition in Healthy Older Adults. eNeuro. 2018;5(2). doi:10.1523/ENEURO.0035-17.2018

Abstract

The aging brain is characterized by altered dopamine signaling. The amino acid tyrosine, a catecholamine precursor, is known to improve cognitive performance in young adults, especially during high environmental demands. Tyrosine administration might also affect catecholamine transmission in the aging brain, thereby improving cognitive functioning. In healthy older adults, impairments have been demonstrated in two forms of response inhibition: reactive inhibition (outright stopping) and proactive inhibition (anticipatory response slowing) under high information load. However, no study has directly compared the effects of a catecholamine precursor on reactive and load-dependent proactive inhibition. In this study we explored the effects of tyrosine on reactive and proactive response inhibition and signal in dopaminergically innervated fronto-striatal regions. Depending on age, tyrosine might lead to beneficial or detrimental neurocognitive effects. We aimed to address these hypotheses in 24 healthy older human adults (aged 61-72 years) using fMRI in a double blind, counterbalanced, placebo-controlled, within-subject design. Across the group, tyrosine did not alter reactive or proactive inhibition behaviorally but did increase fronto-parietal proactive inhibition-related activation. When taking age into account, tyrosine affected proactive inhibition both behaviorally and neurally. Specifically, increasing age was associated with a greater detrimental effect of tyrosine compared with placebo on proactive slowing. Moreover, with increasing age, tyrosine decreased fronto-striatal and parietal proactive signal, which correlated positively with tyrosine's effects on proactive slowing. Concluding, tyrosine negatively affected proactive response slowing and associated fronto-striatal activation in an age-dependent manner, highlighting the importance of catecholamines, perhaps particularly dopamine, for proactive response inhibition in older adults.

Key Findings

Concluding, tyrosine negatively affected proactive response slowing and associated fronto-striatal activation in an age-dependent manner, highlighting the importance of catecholamines, perhaps particularly dopamine, for proactive response inhibition in older adults.

Outcomes Measured

  • Requires manual extraction

Population

Field Value
Population young adults
Sample Size See abstract
Age Range aged 61-72
Condition cognitive

MeSH Terms

  • Aged
  • Aging
  • Anticipation, Psychological
  • Double-Blind Method
  • Executive Function
  • Female
  • Humans
  • Magnetic Resonance Imaging
  • Male
  • Memory, Short-Term
  • Middle Aged
  • Parietal Lobe
  • Prefrontal Cortex
  • Proactive Inhibition
  • Psychomotor Performance
  • Putamen
  • Reactive Inhibition
  • Tyrosine

Evidence Classification

  • Level: Rct
  • Publication Types: Journal Article, Randomized Controlled Trial, Research Support, Non-U.S. Gov't
  • Vertical: tyrosine

Provenance

Source extracted via PubMed E-utilities API on 2026-04-10