Type-I nNOS neurons orchestrate cortical neural activity and vasomotion

Area of Science:

• Neuroscience
• Vascular Biology
• Cellular Neuroscience

Background:

• The brain's global coordination of neural and vascular dynamics remains poorly understood.
• Interneurons, particularly type-I nNOS neurons, play a unique but understudied role in brain function.

Purpose of the Study:

• To investigate the function of type-I nNOS neurons in orchestrating global neural and vascular dynamics.
• To determine the impact of ablating type-I nNOS neurons on brain activity and blood flow regulation.

Main Methods:

• Utilized a novel pharmacological strategy for unilateral ablation of type-I nNOS neurons in the mouse somatosensory cortex.
• Analyzed changes in neural activity (local field potential, LFP) and vascular dynamics (cerebral blood volume, CBV).
• Assessed inter-hemispheric coherence and resting-state oscillations.

Main Results:

• Ablation led to altered neural activity, including decreased delta-band power in LFP.
• Reduced sustained vascular responses to sensory stimulation and abolished post-stimulus undershoot in CBV.
• Decreased gamma-band power envelope coherence between hemispheres and reduced resting-state CBV oscillations and vasomotion.

Conclusions:

• Type-I nNOS neurons are essential for integrating long-range brain signals and regulating whole-brain neural and vascular dynamics.
• The findings suggest a critical role for these neurons in maintaining brain homeostasis.
• Loss of type-I nNOS neurons may contribute to neurodegenerative diseases and sleep disturbances.