Oxytocin and elderly MRI-based hippocampus and amygdala volume: a 7-year follow-up study

Abstract

Oxytocin is deeply involved in human relations. In recent years, it is becoming clear that oxytocin is also involved in social cognition and social behavior. Oxytocin receptors are also thought to be present in the hippocampus and amygdala, and the relationship between oxytocin and the structure and function of the hippocampus and amygdala has been reported. However, few studies have investigated oxytocin and its relationship to hippocampus and amygdala volume in elderly people. The aim of this study is to investigate the association between serum oxytocin levels and hippocampus and amygdala volume in elderly people. The survey was conducted twice in Kurokawa-cho, Imari, Saga Prefecture, Japan, among people aged 65 and older. We collected data from 596 residents. Serum oxytocin level measurements, brain MRI, Mini-Mental State Examination and Clinical Dementia Rating were performed in Time 1 (2009–2011). Follow-up brain MRI, Mini-Mental State Examination and Clinical Dementia Rating were performed in Time 2 (2016–2017). The interval between Time 1 and Time 2 was about 7 years. Fifty-eight participants (14 men, mean age 72.36 ± 3.41 years, oxytocin 0.042 ± 0.052 ng/ml; 44 women, mean age 73.07 ± 4.38 years, oxytocin 0.123 ± 0.130 ng/ml) completed this study. We analyzed the correlation between serum oxytocin levels (Time 1) and brain volume (Time 1, Time 2, and Time 1–2 difference) using voxel-based morphometry implemented with Statistical Parametric Mapping. Analysis at the cluster level (family-wise error; P < 0.05) showed a positive correlation between serum oxytocin levels (Time 1) and brain volume of the region containing the left hippocampus and amygdala (Time 2). This result suggests that oxytocin in people aged 65 and older may be associated with aging-related changes in hippocampus and amygdala volume.

Association Between sTREM2, an Immune Biomarker of Microglial Activation, and Aging-Related Brain Volume Changes in Community-Dwelling Older Adults: A 7-Year Follow-Up Study

“…This was a longitudinal study conducted in Kurokawa-cho, Imari, Saga Prefecture, Japan, among people aged 65 years and above, as reported previously ( Nabeta et al, 2014 ; Matsushima et al, 2015 ; Imamura et al, 2017 ; Orihashi et al, 2020 ). Kurokawa-cho is in northwestern Saga Prefecture and is a rural town somewhat cut-off from urban areas.…”

“…Brain MRI processing and analysis were conducted using voxel-based morphometry (VBM) ( Ashburner and Friston, 2000 ) implemented with Statistical Parametric Mapping (SPM12; Wellcome Department of Cognitive Neurology, London, United Kingdom) in MATLAB R2016a (MathWorks, Natick, MA, United States). We used the same methodology described in a previous study ( Orihashi et al, 2020 ).…”

No association of serum sTREM2 and MRI-based brain volume in elderly people living in a rural community: a 7-year follow-up study

“…In our previous studies using similar methods, we observed that serum oxytocin levels in the elderly were positively correlated with the future hippocampus and amygdala volumes [15]. The hippocampus and amygdala are closely related to cognitive function.…”

“…This was a longitudinal study. The survey was conducted in Kurokawa -cho, Imari, Saga Prefecture, Japan, among people aged 65 years and above, as reported previously [12][13][14][15]. Kurokawa-cho is in northwestern Saga Prefecture and is a rural town somewhat cutoff from urban areas.…”

“…Wellcome Department of Cognitive Neurology, London, UK) in MATLAB R2016a (MathWorks, Natick, MA, USA). We used the same methodology described in a previous study [15]. T1-weighted MR images were first segmented for gray matter and white matter using the segmentation procedures implemented in SPM12.…”