Influence of the hypothalamus-pituitary-gonadal axis reactivation and corresponding surging sex hormones on the amplitude of low-frequency oscillations in early pubertal girls: A resting state fMRI study.

BACKGROUND: There has been a myriad of neuroimaging studies that have suggested that pubertal stages and sex steroid fluctuations contribute to pubertal brain maturation. Investigations on the influence of hypothalamus-pituitary-gonadal (HPG) axis reactivation and the correlated elevated sex hormones on brain maturation have not unraveled these interactions to date. Here, we aimed to explore the impact of the reactivated HPG axis on spontaneous brain activity changes, by analyzing the amplitude of low-frequency fluctuation (ALFF) in developing girls aged 8-11 years old. METHODS: The gonadotropin-releasing hormone (GnRH) stimulation test was used to determine the HPG axis status and categorize subjects into two groups (HPG+ or HPG- group). Intelligence quotient (IQ) and the parent-rated Child Behavior Checklist (CBCL) were used to evaluate cognitive and behavioral performance. Two-sample t-tests were used to compare intergroup differences, the relations between brain areas' activities, age and hormonal levels were conducted by Pearson or Spearman correlation analyses. RESULTS: Compared with the HPG- group, the HPG+ group showed decreased ALFF values in the left superior temporal gyrus (STG) but increased ALFF values in the right superior frontal gyrus (SFG). In addition, in the HPG+ group, prolactin (PRL) levels were positively correlated with ALFF values in the right SFG, and there was significant negative correlation between ALFF values in the left STG and CBCL activities scores. LIMITATIONS: Due to the cross-sectional design of the present study, further study is needed to determine the relationships between age, reawakening of the HPG axis and related sex hormones and spontaneous brain activity change. CONCLUSIONS: These findings suggested that the reactivated HPG axis and elevated PRL level could affect changes in brain activity and this effect may be the neuroendocrine basis of mood, cognition, and social behavior changes in early pubertal girls.

Common 1H-MRS Characteristics in Patients With Alzheimer's Disease and Vascular Dementia Diagnosed With Kidney Essence Deficiency Syndrome: A Preliminary Study.

Context • Traditional Chinese medicine (TCM) indicates that both Alzheimer's disease (AD) and vascular dementia (VD) should be categorized as dementia and that they have a common etiology and pathogenesis under TCM classification of syndromes, such as with kidney essence deficiency syndrome (KEDS). The pathological location is mainly in the brain. However, it remains unclear whether AD and VD patients with KEDS exhibit a metabolic commonality in the same region of the brain. Objective • The study intended to investigate the metabolic characteristics of the brain using proton magnetic resonance spectroscopy (1H-MRS) in patients with AD and VD who had been diagnosed with KEDS. Design • The research team designed a pilot study, with the participants being allocated to 3 groups: (1) an AD group, (2) a VD group, and (3) a control group. All data analysis was carried out by a trained radiologist who was blinded to each participant's diagnosis. Setting • The study took place at the Tongde Hospital of Zhejiang Province (Zhejiang Sheng, China). Participants • Participants were patients at the Tongde Hospital with mild AD or VD who had been diagnosed with KEDS. The normal controls were patients' spouses or guardians with normal cognitive function. Outcome Measures • All participants underwent 1H-MRS. The N-acetyl aspartate (NAA)/myo-inositol (mI), NAA/creatine (Cr), choline (Cho)/Cr, and mI/Cr ratios were bilaterally measured in the posterior cingulate gyrus (PCG) and anterior cingulate gyrus (ACG) by the Syngo spectroscopy postprocessing package. Demographic characteristics and 1H-MRS data were assessed across the AD, VD, and normal control groups. Results • Thirteen patients with mild AD with KEDS, 15 patients with mild VD with KEDS, and 18 normal controls were recruited from May 2013 through May 2014. The AD and VD groups did not significantly differ in the NAA/mI, NAA/Cr, Cho/Cr, and mI/Cr ratios in either the PCG or the ACG, with the exception being the Cho/Cr ratio in the right ACG, for which the ratio of the AD group was significantly lower when compared with that of the VD group (P < .05). Conclusions • Mild AD and VD with KEDS showed similar patterns for the 1H-MRS on the cingulate cortex, providing evidence for a common pathogenesis for the KEDS that is associated with AD and VD, providing a modern biological basis for the philosophy of providing the same treatment for different diseases.