Impaired Neurovascular Coupling and Increased Functional Connectivity in the Frontal Cortex Predict Age‐Related Cognitive Dysfunction

Abstract

Impaired cerebrovascular function contributes to the genesis of age‐related cognitive decline. In this study, the hypothesis is tested that impairments in neurovascular coupling (NVC) responses and brain network function predict cognitive dysfunction in older adults. Cerebromicrovascular and working memory function of healthy young (n = 21, 33.2±7.0 years) and aged (n = 30, 75.9±6.9 years) participants are assessed. To determine NVC responses and functional connectivity (FC) during a working memory (n‐back) paradigm, oxy‐ and deoxyhemoglobin concentration changes from the frontal cortex using functional near‐infrared spectroscopy are recorded. NVC responses are significantly impaired during the 2‐back task in aged participants, while the frontal networks are characterized by higher local and global connection strength, and dynamic FC (p < 0.05). Both impaired NVC and increased FC correlate with age‐related decline in accuracy during the 2‐back task. These findings suggest that task‐related brain states in older adults require stronger functional connections to compensate for the attenuated NVC responses associated with working memory load.

Modal Analysis of Cerebrovascular Effects for Digital Health Integration of Neurostimulation Therapies—A Review of Technology Concepts

“…Such insights are crucial for understanding the mechanistic underpinnings of tES in therapeutic contexts, particularly its role in enhancing neurovascular coupling and cognitive function. Indeed, a hallmark of dementia syndromes is an energy deficit in neurons, leading to synaptic loss and resulting in cognitive decline and behavioral changes [ 76 ]; therefore, an energy boost is necessary [ 77 ], e.g., via facilitating neurovascular [ 78 ] and neurometabolic [ 79 ] coupling rather than solely excitatory tDCS that may increase the energy deficit leading to synaptic loss. Also, Gamma entrainment may positively impact excitation/inhibition imbalances by preventing neurochemical changes linked to Aβ, such as hyperexcitability, and triggering neuroprotective mechanisms [ 80 ].…”

Photobiomodulation in the aging brain: a systematic review from animal models to humans

“…However, it is important to acknowledge that cerebrovascular dysfunction plays a role in the development of age-related cognitive decline. Some studies have shown deficits in neurovascular coupling [114,115], while frontal networks exhibit stronger local and global connectivity. This may suggest that in the elderly, stronger functional connections are needed to compensate for the weakened neurovascular coupling during the performance of a higher demanding task [115].…”