Brain white matter microstructure is associated with susceptibility to motion-induced nausea

Area of Science:

• Neuroscience
• Neuroimaging
• White Matter Research

Background:

• Nausea susceptibility varies significantly among individuals, with its neural basis poorly understood.
• Previous research linked visual motion stimuli to activation in the visual motion area (MT+/V5) and anterior insula, with increased nausea correlating to insula activation.
• Individual differences in nausea susceptibility are not fully explained by current neuroimaging findings.

Purpose of the Study:

• To investigate if microstructural differences in the inferior fronto-occipital fasciculus (IFOF) explain individual variations in visual motion-induced nausea.
• To test the hypothesis that the white matter tract connecting visual and nausea-processing areas is associated with nausea susceptibility.

Main Methods:

• Diffusion tensor imaging (DTI) was used to analyze white matter microstructure in 30 healthy adults.
• Participants were categorized into high and low nausea susceptibility groups using the Motion Sickness Susceptibility Scale.
• Diffusion metrics (axial diffusivity, radial diffusivity, mean diffusivity, fractional anisotropy) were quantified along the right IFOF for between-group comparisons.

Main Results:

• High nausea susceptibility individuals reported greater nausea intensity in response to visual motion stimuli.
• Subjects with high nausea susceptibility showed significantly lower axial diffusivity (AD) and mean diffusivity (MD) in the right IFOF compared to low susceptibility individuals.
• These findings indicate significant differences in white matter microstructure within the IFOF between the two groups.

Conclusions:

• Microstructural variations within the inferior fronto-occipital fasciculus (IFOF) may contribute to individual differences in nausea susceptibility.
• Altered white matter integrity in tracts connecting visual and nausea processing regions could underlie susceptibility to nausea or result from repeated nausea experiences.
• This study highlights the role of white matter microstructure in the neural underpinnings of nausea susceptibility.