Sex differences in amygdala shape: Insights from Turner syndrome

Abstract

Objective: Sex differences in the manifestation of psychiatric disorders, including anxiety disorders, are among the most prominent findings in psychiatry. The study of Turner syndrome (TS), caused by X-monosomy, has the potential to reveal mechanisms that underline male/female differences in neuropsychiatric disorders. The amygdala has been implicated in numerous neuropsychiatric disorders. Previous studies suggest an effect of TS on amygdala volume as well as on amygdala-related behaviors such as anxiety. Our objective is to investigate the amygdala shape in TS. Specifically, we tested whether amygdala enlargements in TS are localized to specific nuclei implicated in anxiety, such as the basomedial nucleus. Experimental design: We use a surface-based analytical modeling approach to contrast 41 pre-estrogen treatment girls with TS (mean age 8.6 ± 2.4) with 34 age-and sex-matched typically developing (TD) controls (mean age 8.0 ± 2.8). Anxiety symptoms were assessed using the Revised Children’s Manifest Anxiety Scale - 2 (RCMAS-2) in both groups. Principal observations: TS was associated with anomalous enlargement of the amygdala. Surface-based modeling revealed shape differences (increased radial-distances) in bilateral basal and basomedial nuclei within the basolateral complex. RCMAS-2 Total Anxiety t-score was significantly higher in participants with TS compared with TD controls (P = 0.012). Conclusions: Group differences in global amygdala volumes were driven by local morphological increases in areas that are critically involved in face emotion processing and anxiety. In the context of increased amygdala volumes in TS, our results also showed increased worry and social anxiety in young girls with TS compared with TD. Hum Brain Mapp 37:1593–1601, 2016.

Carriage of Supernumerary Sex Chromosomes Decreases the Volume and Alters the Shape of Limbic Structures

“…In particular, an area along the rostral surface of the amygdala centered on the basomedial nucleus was focally contracted in patients carrying supernumerary sex chromosomes. Our report of spatially specific contraction in X-chromosome supernumeracy, in combination with a previous report of spatially specific expansion of the basomedial nucleus in Xchromosome monosomy (Green et al, 2016), suggests a spatially specific X-chromosome-dosage effect on amygdala shape. In the hippocampus, we observed a large band of areal contraction along the midsection of the rostral-caudal axis, as well as a small area of focal expansion along the caudal surface.…”

“…Patients with sex chromosome aneuploidies (SCA) are at elevated risk for these psychiatric disorders (Hong & Reiss, 2014), although it remains unclear if amygdalar and hippocampal development are sensitive to the presence of supernumerary sex chromosomes. Some evidence that the volume and shape of these structures may be sensitive to SCA comes from recent studies of Turner Syndrome which report that loss of one X-chromosome in females enlarges the amygdala in a spatially specific manner (Green et al, 2016;Kesler et al, 2004). However, it remains unknown if these effects generalize to the hippocampus (the other core element of the limbic brain network), or if either of these structures are sensitive to carriage of excess X-and or Y-chromosomes.…”

Case Management Guidelines on Neurodevelopmental and Psychosocial Problems of Turner Syndrome

“…Yüz tanıma defisitleri duygusal affektlerin yüz ifadesini tanımada seçici bozukluklara yol açmaktadır (13). Amigdalanın yüz ifadesini tanımlamak ve sosyal yargı ile ilgili olduğu bilinmektedir ve nörogörüntüleme çalışmalarında TS'da genişlemiş amigdala volümlerinin arttığı gösterilmiştir (14,25). Ayrıca çalışmalarda orbitofrontal korteks ve süperior temporal sulkusta anormal nörogelişim gösterilmiştir.…”

Pathological Brain Detection by Artificial Intelligence in Magnetic Resonance Imaging Scanning (Invited Review)

“…Table 6 shows the common features used in brain images. [115], eccentricity [116], distance [117], diameter [118], orientation [119], length [120], thickness [121], Moment central moment [122], Hu moment [123], Zernike moment [124], pseudo Zernike moment [125], statistical moment [126], Wavelet discrete wavelet transform [127], stationary wavelet transform [128], Legendre wavelet transform (LWT, also called spherical wavelet transform) [129], discrete wavelet packet transform [130], Gabor wavelet transform [131]; dual-tree complex wavelet transform [132], wavelet-space correlation [133], Statistics mean [134], variance [135], skewness [136], kurtosis [137], uniformity [138] …”