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Microstructural alterations in medial forebrain bundle are associated with interindividual pain sensitivity.
Maria Geisler1, Elizabeth Rizzoni2, Nikolaos Makris2,3,4
1Department of Clinical Psychology, Friedrich-Schiller-University Jena, Jena, Germany.
Human Brain Mapping
|November 10, 2020
Summary
Individual pain sensitivity varies due to differences in brain pathways. Microstructure variations in the medial forebrain bundle (MFB) correlate with pain perception, suggesting a role in pain inhibition.
Area of Science:
- Neuroscience
- Neuroimaging
- Pain Research
Background:
- Individual pain sensitivity exhibits significant inter-individual variability.
- Brain structures and white matter pathways underlying pain perception are complex and not fully understood.
- The medial forebrain bundle (MFB) is a key tract connecting basal forebrain and brain stem, implicated in various behaviors.
Purpose of the Study:
- To investigate the association between the microstructure of the medial forebrain bundle (MFB) and inter-individual differences in pain sensitivity.
- To determine if variations in MFB white matter integrity correlate with pain intensity ratings.
Main Methods:
- Assessed inter-individual pain sensitivity using heat stimuli (45, 47, and 48.9°C) in 38 healthy men.
- Reconstructed the MFB using multitensor tractography from diffusion magnetic resonance imaging (dMRI).
- Calculated free-water corrected dMRI measures: fractional anisotropy (FAt), radial diffusivity (RDt), and axial diffusivity (ADt).
Main Results:
- Lower pain intensity ratings correlated with higher FAt and lower RDt of the MFB.
- These microstructural changes (FAt, RDt) may indicate alterations in myelination within the MFB.
- Higher MFB myelination suggested an association with lower pain ratings.
Conclusions:
- Alterations in the microstructure of the medial forebrain bundle (MFB) contribute to variations in pain perception.
- The MFB may play a role as an inhibitory pathway modulating pain.
- Findings highlight the MFB's importance in understanding individual differences in pain sensitivity.
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