Delay Discounting and Frontostriatal Fiber Tracts: A Combined DTI and MTR Study on Impulsive Choices in Healthy Young Adults
Open Access
- 5 June 2012
- journal article
- research article
- Published by Oxford University Press (OUP) in Cerebral Cortex
- Vol. 23 (7), 1695-1702
- https://doi.org/10.1093/cercor/bhs163
Abstract
Delay discounting, a measure of impulsive choice, has been associated with decreased control of the prefrontal cortex over striatum responses. The anatomical connectivity between both brain regions in delaying gratification remains unknown. Here, we investigate whether the quality of frontostriatal (FS) white matter tracts can predict individual differences in delay-discounting behavior. We use tract-based diffusion tensor imaging and magnetization transfer imaging to measure the microstructural properties of FS fiber tracts in 40 healthy young adults (from 18 to 25 years). We additionally explored whether internal sex hormone levels affect the integrity of FS tracts, based on the hypothesis that sex hormones modulate axonal density within prefrontal dopaminergic circuits. We calculated fractional anisotropy (FA), mean diffusivity (MD), longitudinal diffusivity, radial diffusivity (RD), and magnetization transfer ratio (MTR), a putative measure of myelination, for the FS tract. Results showed that lower integrity within the FS tract (higher MD and RD and lower FA), predicts faster discounting in both sexes. MTR was unrelated to delay-discounting performance. In addition, testosterone levels in males were associated with a lower integrity (higher RD) within the FS tract. Our study provides support for the hypothesis that enhanced structural integrity of white matter fiber bundles between prefrontal and striatal brain areas is associated with better impulse control.Keywords
This publication has 73 references indexed in Scilit:
- Behavioral and neural correlates of delay of gratification 40 years laterProceedings of the National Academy of Sciences of the United States of America, 2011
- DAT1 and COMT Effects on Delay Discounting and Trait Impulsivity in Male Adolescents with Attention Deficit/Hyperactivity Disorder and Healthy ControlsNeuropsychopharmacology, 2010
- Dopaminergic Network Differences in Human ImpulsivityScience, 2010
- The emergence of gonadal hormone influences on dopaminergic function during pubertyHormones and Behavior, 2010
- Gonadectomy and Hormone Replacement Affects In Vivo Basal Extracellular Dopamine Levels in the Prefrontal Cortex but Not Motor Cortex of Adult Male RatsCerebral Cortex, 2010
- Congruence of BOLD Response across Intertemporal Choice Conditions: Fictive and Real Money Gains and LossesJournal of Neuroscience, 2009
- In vivo measurement of axon diameter distribution in the corpus callosum of rat brainBrain, 2009
- Dissociable neural representations of future reward magnitude and delay during temporal discountingNeuroImage, 2009
- Tract-based Analysis of Magnetization Transfer Ratio and Diffusion Tensor Imaging of the Frontal and Frontotemporal Connections in SchizophreniaSchizophrenia Bulletin, 2008
- Diffusion tensor imaging: Concepts and applicationsJournal of Magnetic Resonance Imaging, 2001