On the Effect of Sex on Prefrontal and Cerebellar Neurometabolites in Healthy Adults: An MRS Study.

Dominique Endres,Simon Maier,Evgeniy Perlov,Bernd Feige,Stephan Backenecker,Ludger Tebartz Van Elst,Irina Mader,Anna Bubl,Thomas Lange,Kathrin Nickel

doi:10.3389/fnhum.2016.00367

Abstract

In neuropsychiatric research, the aspects of sex have received increasing attention over the past decade. With regard to the neurometabolic differences in the prefrontal cortex and the cerebellum of both men and women, we performed a magnetic resonance spectroscopic (MRS) study of a large group of healthy subjects. For neurometabolic measurements, we used single-voxel proton MRS. The voxels of interest (VOI) were placed in the pregenual anterior cingulate cortex (pACC) and the left cerebellar hemisphere. Absolute quantification of creatine (Cre), total choline (t-Cho), glutamate and glutamine (Glx), N-acetylaspartate, and myo-inositol (mI) was performed. Thirty-three automatically matched ACCs and 31 cerebellar male–female pairs were statistically analyzed. We found no significant neurometabolic differences in the pACC region (Wilks' lambda: p = 0.657). In the left cerebellar region, we detected significant variations between the male and female groups (p = 0.001). Specifically, we detected significantly higher Cre (p = 0.005) and t-Cho (p = 0.000) levels in men. Additionally, males tended to have higher Glx and mI concentrations. This is the first study to report neurometabolic sex differences in the cerebellum. The effects of sexual hormones might have influenced our findings. Our data indicates the importance of adjusting for the confounding effects of sex in MRS studies.

Highlights

In neuropsychiatric research, aspects of sex have received increasing attention over the past decade
Upon comparing the male and female groups, we found no significant differences in the pregenual anterior cingulate cortex (pACC) voxels of interest (VOI) (Wilks’ lambda: p = 0.657)
We found no differences between sexes in the pACC

Summary

Introduction

Aspects of sex have received increasing attention over the past decade. There are interesting sex distribution ratios in populations with neurodevelopmental disorders such as attention deficit hyperactivity disorder (ADHD) and autism spectrum disorders (ASD), which are more common in boys than in girls (Biederman and Faraone, 2005; Tebartz van Elst et al, 2013). Women are more frequently affected by depression and anxiety (Karger, 2014). Knowledge about the physiology of sex-related differences is the basis for understanding the pathophysiology of neuropsychiatric sex-related differences. Morphometric studies have shown that males’ brains are 9–12% larger than females, the relevance of this is unclear (Lenroot and Giedd, 2010).

Objectives

Results

Discussion

Conclusion