Sex differences in dorsal striatal volume and interest in quitting smoking
Open Access
- Author:
- Huang, Siyuan Siyuan
- Graduate Program:
- Psychology
- Degree:
- Doctor of Philosophy
- Document Type:
- Dissertation
- Date of Defense:
- May 29, 2024
- Committee Members:
- Kristin Buss, Program Head/Chair
Rick Gilmore, Major Field Member
Stephen Wilson, Chair & Dissertation Advisor
Frank Hillary, Major Field Member
Steven Branstetter, Outside Unit & Field Member - Keywords:
- Cigarette smoking
Sex-related differences
Voxel-based morphometry
Drosal striatum
Gray matter volume - Abstract:
- Cigarette smoking is one of the leading causes of preventable death and is accompanied by a range of health problems in the US. Over the recent decades, female smoking has become an increasingly pressing public health challenge. To understand the brain mechanisms underlying the cessation difficulties prevalently reported by female smokers, the present study used voxel-based morphometry (VBM) measure to investigate sex-specific volumetric differences in smokers and their connections to self-reported quit interest. Structural magnetic resonance brain imaging (MRI) data from forty-one women and fifty-two men (30.1 ± 7.5 yrs) who reported smoking an average of 15-40 cigarettes per day for the past 24 months were collected. Analyses were carried out either on the average gray matter volume (GMV) value of predetermined brain regions of interest (ROIs; i.e., bilateral caudate, putamen, nucleus accumbens, thalamus) or to assess the GMV differences voxel by voxel across the whole brain. To evaluate whether the VBM results were consistent across analysis approaches, secondary analyses were conducted to investigate the potential impacts of image preprocessing pipeline (SPM CAT12 vs. FSL-VBM), spatial smoothing kernel, method used to define ROIs, inclusion of covariates (e.g., age, MRI image quality), and multiple tests correction strategy (parametric vs. nonparametric approach), respectively, on ROI- and voxel-wise statistics. ROI-based analyses revealed that female smokers presented larger GMVs in all ROIs than male smokers, controlling for all covariates. Most importantly, there appeared to be a more negative association between GMV in the putamen and current interest in quitting for female relative to male smokers. However, the observation of this sex and GMV interaction relied upon using specific preprocessing pipeline (i.e., SPM CAT12) and ROI definition approach. Voxel-wise cluster analysis did not replicate this interaction outcome but instead detected wide-range volumetric sex differences (female > male) in regional GMVs across the whole brain, which varied with the choices of processing pipeline and smoothing kernel size. Results suggest that compared to men, female smokers’ greater cessation difficulty may involve increased GMV in the dorsolateral/putamen subcomponent of the striatum that regulates habit-directed, stimulus-bound smoking behavior. Additional results evince that certain analysis factors, such as the MRI software package, may alter the detection of volumetric sex differences in the context of cigarette smoking. The current study reports a novel sex-moderated association between the neuroanatomy of the putamen and the desire to discontinue smoking. Results support the development of female-specific treatments that address compulsive tobacco seeking resulting from automatic cue-induced reactivity. Further, this study highlights the importance of performing multiple reasonable analyses on the same data and clearly reporting all analytical outcomes to augment the reliability and robustness of neuroimaging findings.