Department of Cardiovascular Sciences, University of Leicester, Leicester, United Kingdom.
NIHR Leicester Biomedical Research Centre, British Heart Foundation Cardiovascular Research Centre, Glenfield Hospital, Leicester, United Kingdom.
PLoS One. 2022 Mar 28;17(3):e0266048. doi: 10.1371/journal.pone.0266048. eCollection 2022.
Cognitive paradigms induce changes in cerebral blood flow (CBF) associated with increased metabolic demand, namely neurovascular coupling (NVC). We tested the hypothesis that the effect of complexity and duration of cognitive paradigms will either enhance or inhibit the NVC response. Bilateral CBF velocity (CBFV) in the middle cerebral arteries (MCAs) via transcranial Doppler ultrasound (TCD), blood pressure (BP), electrocardiogram (ECG) and end-tidal CO2 (EtCO2) of 16 healthy participants (aged 21-71 years) were simultaneously recorded at rest and during randomized paradigms of different complexities (naming words beginning with P-,R-,V- words and serial subtractions of 100-2,100-7,1000-17), and durations (5s, 30s and 60s). CBFV responses were population mean normalized from a 30-s baseline period prior to task initiation. A significant increase in bilateral CBFV response was observed at the start of all paradigms and provided a similar pattern in most responses, irrespective of complexity or duration. Although significant inter-hemispherical differences were found during performance of R-word and all serial subtraction paradigms, no lateralisation was observed in more complex naming word tasks. Also, the effect of duration was manifested at late stages of 100-7, but not for other paradigms. CBFV responses could not distinguish different levels of complexity or duration with a single presentation of the cognitive paradigm. Further studies of the ordinal scalability of the NVC response are needed with more advanced modelling techniques, or different types of neural stimulation.
认知范式会引起与代谢需求增加相关的脑血流 (CBF) 变化，即神经血管耦合 (NVC)。我们假设认知范式的复杂性和持续时间的影响将增强或抑制 NVC 反应。通过经颅多普勒超声 (TCD) 测量 16 名健康参与者（年龄 21-71 岁）双侧大脑中动脉 (MCA) 的 CBF 速度 (CBFV)、血压 (BP)、心电图 (ECG) 和呼气末 CO2 (EtCO2)，同时记录休息时和随机不同复杂程度（以 P-、R-、V- 开头的单词命名和 100-2、100-7、1000-17 的连续减法）和持续时间（5s、30s 和 60s）的范式。CBFV 反应是从任务开始前的 30s 基线期进行群体平均归一化。在所有范式开始时观察到双侧 CBFV 反应的显著增加，并提供了大多数反应的相似模式，无论复杂程度或持续时间如何。尽管在执行 R 字和所有连续减法范式期间发现了明显的半球间差异，但在更复杂的命名单词任务中没有观察到偏侧化。此外，在 100-7 的后期阶段观察到持续时间的影响，但其他范式则没有。CBFV 反应无法通过单次呈现认知范式来区分不同的复杂程度或持续时间。需要使用更先进的建模技术或不同类型的神经刺激，进一步研究 NVC 反应的有序可扩展性。
