Understanding Glucose-induced Neuronal Activation During Executive 2-back Task Performance In Hypertensive Otherwise Healthy Older Adults: A Functional Magnetic Resonance Imaging Study

• Main Author: Yuen, William
• Other Authors: Greenwood, Carol
• Language: en_ca
• Published: 2013
• Subjects: aging; fMRI; hypertension; glucose; executive function; working memory; insulin resistance; low density lipoprotein; nutritient; memory; 0570
• Online Access: http://hdl.handle.net/1807/43355

The primary objective of this research was to explore the impact of glucose ingestion on 2-back task performance (accuracy, discrimination, and reaction times (RT) to target), its relationship to neural activation, using functional magnetic resonance imaging, and potential modulation by insulin resistance (IR) and low density lipoprotein (LDL) in hypertensive but otherwise healthy older adults. While there was no effect of glucose ingestion on task performance or task-relevant neural activation patterns, this study uniquely observed that IR and LDL associated with all 3 measures of 2-back performance and task-relevant neural activation patterns. The left and right precuneus, left cingulate, and left insula were identified as task-associated regions according to our specific target minus nontarget contrast. Of particular importance was the task activation in the right precuneus as it both showed sensitivity to IR and predicted task RTs to targets, suggesting it plays a modulatory role linking IR to task performance.