Yoo Hyun Joo, Nashiro Kaoru, Dutt Shubir, Min Jungwon, Cho Christine, Thayer Julian F, Lehrer Paul, Chang Catie, Mather Mara
University of Southern California, Los Angeles, CA 90089.
University of California, Irvine, Irvine, CA 92697.
medRxiv. 2023 Sep 11:2023.03.02.23286715. doi: 10.1101/2023.03.02.23286715.
Using data from a clinical trial, we tested the hypothesis that daily sessions modulating heart rate oscillations affect older adults' volume of a region-of-interest (ROI) comprised of adjacent hippocampal subregions with relatively strong locus coeruleus (LC) noradrenergic input. Younger and older adults were randomly assigned to one of two daily biofeedback practices for 5 weeks: 1) engage in slow-paced breathing to increase the amplitude of oscillations in heart rate at their breathing frequency (Osc+); 2) engage in self-selected strategies to decrease heart rate oscillations (Osc-). The interventions did not significantly affect younger adults' hippocampal volume. Among older adults, the two conditions affected volume in the LC-targeted hippocampal ROI differentially as reflected in a significant condition x time-point interaction on ROI volume. These condition differences were driven by opposing changes in the two conditions (increased volume in Osc+ and decreased volume in Osc-) and were mediated by the degree of heart rate oscillation during training sessions.
利用一项临床试验的数据，我们检验了以下假设：每日调节心率振荡的疗程会影响老年人由相邻海马亚区域组成的感兴趣区域（ROI）的体积，这些相邻海马亚区域具有相对较强的蓝斑（LC）去甲肾上腺素能输入。年轻人和老年人被随机分配到两种每日生物反馈练习中的一种，为期5周：1）进行慢节奏呼吸，以增加其呼吸频率时心率振荡的幅度（Osc+）；2）采用自我选择的策略来降低心率振荡（Osc-）。这些干预措施对年轻人的海马体积没有显著影响。在老年人中，两种情况对LC靶向海马ROI的体积有不同影响，这反映在ROI体积上显著的情况×时间点交互作用中。这些情况差异是由两种情况的相反变化驱动的（Osc+中体积增加，Osc-中体积减少），并由训练期间心率振荡的程度介导。
