Neurovascular Coupling under Chronic Stress Is Modified by Altered GABAergic Interneuron Activity

Area of Science:

• Neuroscience
• Vascular Biology
• Stress Physiology

Background:

• Neurovascular coupling (NVC) links neural activity to vascular responses, crucial for brain homeostasis.
• Previous studies noted altered cerebrovascular responses in chronically stressed animals, but neuronal mechanisms were unclear.

Purpose of the Study:

• Investigate the neuronal basis of altered NVC dynamics under chronic stress.
• Identify molecular changes contributing to impaired NVC in stressed mice.

Main Methods:

• Utilized in vivo and ex vivo experiments in adult male mice.
• Employed hemodynamic imaging, electrophysiology, acute brain slices, FISH, and pharmacological treatments.
• Assessed stimulus-evoked neural and vascular responses, and nNOS mRNA expression.

Main Results:

• Chronically stressed mice showed reduced stimulus-evoked neural and hemodynamic responses.
• Dysfunction of neuronal nitric oxide synthase (nNOS)-mediated vasodilation was identified as the cause of altered NVC.
• Significantly decreased nNOS mRNA expression was observed in stressed mice.

Conclusions:

• Chronic stress impairs NVC by diminishing nNOS-mediated vasodilation, impacting brain homeostasis.
• Impaired nNOS-mediated NVC may be a factor in stress-related cerebrovascular diseases.