Department of Special Education and Communication Disorders, University of Nebraska-Lincoln, Lincoln, Nebraska.
Center for Brain, Biology, and Behavior, University of Nebraska-Lincoln, Lincoln, Nebraska.
Brain Behav. 2023 Apr;13(4):e2928. doi: 10.1002/brb3.2928. Epub 2023 Mar 1.
Neuroplasticity may be enhanced by increasing brain activation and bloodflow in neural regions relevant to the target behavior. We administered precisely formulated and dosed taste stimuli to determine whether the associated brain activity patterns included areas that underlie swallowing control.
Five taste stimuli (unflavored, sour, sweet-sour, lemon, and orange suspensions) were administered in timing-regulated and temperature-controlled 3 mL doses via a customized pump/tubing system to 21 healthy adults during functional magnetic resonance imaging (fMRI). Whole-brain analyses of fMRI data assessed main effects of taste stimulation as well as differential effects of taste profile.
Differences in brain activity associated with taste stimulation overall as well as specific stimulus type were observed in key taste and swallowing regions including the orbitofrontal cortex, insula, cingulate, and pre- and postcentral gyri. Overall, taste stimulation elicited increased activation in swallowing-related brain regions compared to unflavored trials. Different patterns of blood oxygen level-dependent (BOLD) signal were noted by taste profile. For most areas, sweet-sour and sour trials elicited increases in BOLD compared to unflavored trials within that region, whereas lemon and orange trials yielded reductions in BOLD. This was despite identical concentrations of citric acid and sweetener in the lemon, orange, and sweet-sour solutions.
These results suggest that neural activity in swallowing-relevant regions can be amplified with taste stimuli and may be differentially affected by specific properties within very similar taste profiles. These findings provide critical foundational information for interpreting disparities in previous studies of taste effects on brain activity and swallowing function, defining optimal stimuli to increase brain activity in swallowing-relevant regions, and harnessing taste to enhance neuroplasticity and recovery for persons with swallowing disorders.
通过增加与目标行为相关的神经区域的大脑激活和血流，可以增强神经可塑性。我们给予精确配方和剂量的味觉刺激，以确定相关的大脑活动模式是否包括吞咽控制的基础区域。
在功能磁共振成像 (fMRI) 期间，通过定制的泵/管道系统，以定时调节和温度控制的 3 毫升剂量向 21 名健康成年人给予 5 种味觉刺激（无味、酸、酸甜、柠檬和橙汁悬浮液）。对 fMRI 数据的全脑分析评估了味觉刺激的主要影响以及味觉特征的差异影响。
在包括眶额皮质、岛叶、扣带回、中央前回和中央后回在内的关键味觉和吞咽区域中，观察到与味觉刺激相关的大脑活动总体差异以及特定刺激类型的差异。与无味试验相比，味觉刺激总体上引起与吞咽相关的大脑区域的激活增加。通过味觉特征观察到血氧水平依赖（BOLD）信号的不同模式。对于大多数区域，与无味试验相比，酸甜和酸味试验在该区域内引起 BOLD 增加，而柠檬和橙汁试验则导致 BOLD 减少。尽管柠檬、橙子和酸甜溶液中的柠檬酸和甜味剂浓度相同。
这些结果表明，吞咽相关区域的神经活动可以通过味觉刺激来放大，并且可能受到非常相似的味觉特征中特定属性的差异影响。这些发现为解释味觉对大脑活动和吞咽功能影响的先前研究中的差异、确定增加吞咽相关区域大脑活动的最佳刺激以及利用味觉增强神经可塑性和吞咽障碍患者的恢复提供了关键的基础信息。
