Affective bias and response modulation following tyrosine depletion in healthy adults

UNCG Author/Contributor (non-UNCG co-authors, if there are any, appear on document)
Suzanne Vrshek-Schallhorn, Associate Professor and Undergraduate Program Director (Creator)
The University of North Carolina at Greensboro (UNCG )
Web Site:

Abstract: Acute phenylalanine/tyrosine depletion (ATPD) has been used to transiently lower central nervoussystem dopamine activity in animals and humans. Findings suggest that ATPD may impactdopamine transmission in limbic and striatal regions. Impact on cognitive functions has variedacross studies, although several recent reports suggest that affective processing in the context of ago/no-go response control task may be impaired during ATPD. In this study, response control underaffective vs nonaffective conditions was examined in healthy individuals who underwent eitherATPD or a balanced condition in a between-subjects design. Effects of ATPD were validatedthrough its effects on serum prolactin secretion. ATPD resulted in significantly increased prolactinlevels relative to the balanced mixture. Although there were no differences in self-reported moodbetween the groups, individuals in the ATPD condition demonstrated diminished sensitivity topositively valenced words and seemingly enhanced sensitivity to negatively valenced words in anaffective go/no-go task. They also showed difficulties in modulating ongoing behavior in anonaffective go/no-go task when responses had to be intermittently inhibited then immediatelyrestarted. Basic motor functions were not impacted. Findings are discussed in relation todopamine's role in switching signals within neural networks that are important for responsemodulation and affective control.

Additional Information

Neuropsychopharmacology 31(11)
Language: English
Date: 2006
tyrosine depletion, dopamine, affect, go/no-go, cognitive control

Email this document to