Altered brain morphology and functional connectivity in postmenopausal women: automatic segmentation of whole-brain and thalamic subnuclei and resting-state fMRI.

The transition to menopause is associated with various physiological changes, including alterations in brain structure and function. However, menopause-related structural and functional changes are poorly understood. The purpose of this study was not only to compare the brain volume changes between premenopausal and postmenopausal women, but also to evaluate the functional connectivity between the targeted brain regions associated with structural atrophy in postmenopausal women. Each 21 premenopausal and postmenopausal women underwent magnetic resonance imaging (MRI). T1-weighted MRI and resting-state functional MRI data were used to compare the brain volume and seed-based functional connectivity, respectively. In statistical analysis, multivariate analysis of variance, with age and whole brain volume as covariates, was used to evaluate surface areas and subcortical volumes between the two groups. Postmenopausal women showed significantly smaller cortical surface, especially in the left medial orbitofrontal cortex (mOFC), right superior temporal cortex, and right lateral orbitofrontal cortex, compared to premenopausal women (p < 0.05, Bonferroni-corrected) as well as significantly decreased functional connectivity between the left mOFC and the right thalamus was observed (p < 0.005, Monte-Carlo corrected). Although postmenopausal women did not show volume atrophy in the right thalamus, the volume of the right pulvinar anterior, which is one of the distinguished thalamic subnuclei, was significantly decreased (p < 0.05, Bonferroni-corrected). Taken together, our findings suggest that diminished brain volume and functional connectivity may be linked to menopause-related symptoms caused by the lower sex hormone levels.

Working memory dysfunction associated with brain functional deficits and cellular metabolic changes in patients with generalized anxiety disorder.

Generalized anxiety disorder (GAD) is associated with brain functional and morphological changes in connected with emotional dysregulation and cognitive deficit. This study dealt with the neural functional deficits and metabolic abnormalities in working memory (WM) task with emotion-inducing distractors in patients with GAD. Fourteen patients with GAD and 14 healthy controls underwent functional magnetic resonance imaging (fMRI) and proton magnetic resonance spectroscopy ((1)H-MRS) at 3T. In response to the emotional distractors in WM tasks, the patients concurrently showed higher activity in the hippocampus and lower activities in the superior occipital gyrus, superior parietal gyrus, dorsolateral prefrontal cortex (DLPFC) and precentral gyrus compared to the controls. MRS revealed significantly lower choline/creatine (Cho/Cr) and choline/N-acetylaspartate (Cho/NAA) ratios in the DLPFC. In particular, the Cho ratios were positively correlated with the brain activities based on blood oxygenation level-dependent signal change in the DLPFC. This study provides the first evidence for the association between the metabolic alterations and functional deficit in WM processing with emotion-inducing distractors in GAD. These findings will be helpful to understand the neural dysfunction in connection with WM impairment in GAD.

Brain morphological alterations and cellular metabolic changes in patients with generalized anxiety disorder: A combined DARTEL-based VBM and (1)H-MRS study.

Generalized anxiety disorder (GAD) is characterized by emotional dysregulation and cognitive deficit in conjunction with brain morphometric and metabolic alterations. This study assessed the combined neural morphological deficits and metabolic abnormality in patients with GAD. Thirteen patients with GAD and 13 healthy controls matched for age, sex, and education level underwent high-resolution T1-weighted MRI and proton magnetic resonance spectroscopy ((1)H-MRS) at 3Tesla. In this study, the combination of voxel-based morphometry (VBM) and (1)H-MRS was used to assess the brain morphometric and metabolic alterations in GAD. The patients showed significantly reduced white matter (WM) volumes in the midbrain (MB), precentral gyrus (PrG), dorsolateral prefrontal cortex (DLPFC) and anterior limb of the internal capsule (ALIC) compared to the controls. In MRS study, the choline/creatine (Cho/Cr) and choline/N-acetylaspartate (Cho/NAA) ratios in the DLPFC were significantly lower in the patients. Particularly, the WM volume variation of the DLPFC was positively correlated with both of the Cho/Cr and Cho/NAA ratios in patients with GAD. This study provides an evidence for the association between the morphometric deficit and metabolic changes in GAD. This finding would be helpful to understand the neural dysfunction and pathogenesis in connection with cognitive impairments in GAD.

Brain activation areas of sexual arousal with olfactory stimulation in men: a preliminary study using functional MRI.

INTRODUCTION: There have been extensive studies evaluating the functional neuroanatomy of the brain during visual sexual stimulation. However, little data exist concerning the role of olfactory stimulation in human sexuality. AIM: This preliminary study intended to elucidate the brain areas responding to an olfactory sexual stimulus using functional magnetic resonance imaging (fMRI). METHODS: Eight healthy right-handed heterosexual male volunteers (20-35 years of age), having normal olfaction and no brain diseases, were recruited. During fMRI, a women's perfume was given as an olfactory sexual stimulant in an alternating block design with a 30-second stimulation period followed by a 30-second rest. After the fMRI sessions, the participants provided ratings for both the odorant's intensity and perceived arousal. MAIN OUTCOME MEASURES: The study subjects rated the odorant stimulation and perceived sexual arousal response by Likert-type rating scales. Brain activation maps were made by blood oxygenation level-dependent (BOLD)-based fMRI with an echo-planar imaging pulse sequence. RESULTS: Two out of eight subjects experienced "strong" sexual arousal, and three subjects experienced "moderate" arousal during olfactory stimulation, resulting in a mean score of 2.25 on a 4-point scale. The common brain areas activated in response to the odor stimulus in all eight subjects included the insula, the inferior and middle frontal gyrus, and the hypothalamus. The median cingulate gyrus, thalamus, angular gyrus, lingual gyrus, and cerebellar cortex were activated in subjects who had moderate or strong sexual arousal response. CONCLUSION: Olfactory stimulation with women's perfume produces the activation of specific brain areas in men. The brain areas activated differed according to the degree of perceived sexual arousal response. Further studies are needed to elucidate brain activation response according to the different kinds and intensities of olfactory stimulation.