Britton Mark K, Colverson Aaron, Cohen Ronald A, Velez Xavier, Lamb Damon G, Porges Eric C, Williamson John B
Center for Cognitive Aging and Memory, University of Florida, Gainesville, FL, United States 32610; Department of Epidemiology, University of Florida, Gainesville, FL, United States 32610.
Center for Cognitive Aging and Memory, University of Florida, Gainesville, FL, United States 32610.
Brain Cogn. 2024 Dec;182:106230. doi: 10.1016/j.bandc.2024.106230. Epub 2024 Nov 4.
Changes in neuronal inhibition have been implicated in age-related declines in sensorimotor performance. While indirect evidence suggests that inhibitory mechanisms are also involved in rhythm entrainment, this association has not been tested. Using magnetic resonance spectroscopy, we tested the association between dorsomedial frontal GABA+/H2O concentrations and musical rhythm production in healthy younger (n = 14; 18-35) and older (n = 12; 55-79) adults, hypothesizing that lower GABA+/H2O concentrations would be associated with increased timing error, particularly on more difficult exercises, and intra-individual variability (quantified via mean successive squared difference (MSSD)). Rhythm learning exercises were presented in order of complexity. Linear mixed effects modeling revealed GABA+/H2O-by-exercise number interaction (β = -0.59, p = 0.006) such that participants with lower GABA+/H2O showed greater performance decrement with increasing exercise difficulty. GABA+/H2O trended toward an inverse association with MSSD (β = -0.25, p = 0.089), such that higher GABA+/H2O was associated with lower variability in performance. Older age was associated with increased absolute timing error (β = 0.66, p < 0.001) and greater MSSD (β = 0.86, p = 0.012). However, there was no evidence for age group differences in GABA+/H2O-performance relationships. This finding suggests that GABAergic neuronal inhibition may be important in musical rhythm production across age groups.
神经元抑制的变化与感觉运动能力随年龄增长而下降有关。虽然间接证据表明抑制机制也参与节律同步，但这种关联尚未得到验证。我们使用磁共振波谱技术，测试了健康的年轻成年人（n = 14；18 - 35岁）和年长成年人（n = 12；55 - 79岁）背内侧额叶GABA⁺/H₂O浓度与音乐节奏产生之间的关联，假设较低的GABA⁺/H₂O浓度会与更大的时间误差相关，尤其是在更困难的练习中，以及个体内部变异性（通过平均连续平方差（MSSD）量化）。节奏学习练习按照难度顺序呈现。线性混合效应模型显示GABA⁺/H₂O与练习次数之间存在交互作用（β = -0.59，p = 0.006），即GABA⁺/H₂O较低的参与者随着练习难度增加表现下降得更明显。GABA⁺/H₂O与MSSD呈负相关趋势（β = -0.25，p = 0.089），即较高的GABA⁺/H₂O与较低的表现变异性相关。年长与更大的绝对时间误差（β = 0.66，p < 0.001）和更大的MSSD（β = 0.86，p = 0.012）相关。然而，没有证据表明年龄组在GABA⁺/H₂O与表现关系上存在差异。这一发现表明，GABA能神经元抑制在各年龄组的音乐节奏产生中可能都很重要。
