Role of interneurons in brain tissue oxygen regulation

The regulation of oxygen in brain tissue is a fundamental question in neuroscience and medicine, as it is crucial for maintaining optimal brain function. GABAergic interneurons, which provide inhibitory signals in the cerebral cortex, have been found to not only connect with other neurons but also with arterioles, enabling them to control network activity and vasomotion to regulate blood delivery within the brain. However, the specific mechanisms by which interneurons contribute to local oxygen homeostasis remain unclear. Building upon our published and preliminary data, we propose that interneurons, utilizing their dual neurotransmission function, play a primary role in regulating both brain tissue oxygen (PO2) levels and BOLD fMRI responses. To investigate this hypothesis, we have designed a comprehensive study comprising three specific aims. In Specific Aim 1, we will determine the role of GABA in the magnitude and direction of PO2 responses. Specific Aim 2 focuses on investigating the role of the dual neurotransmission system in PO2 responses. In Specific Aim 3, we will investigate how the absence of excitatory activity in pyramidal cells affects oxygen responses. The proposed studies on neuronal regulation of oxygen in brain tissue hold broad implications for understanding the relationship between neuronal activity and oxygenation. They have significant relevance to both healthy brain functioning and conditions involving vascular dysfunction. By elucidating the mechanisms underlying brain tissue oxygen regulation, these investigations will also offer insights into epileptic and sub-convulsive states. Additionally, improving our fundamental understanding of neuronal tissue oxygen regulation has the potential to enhance neuroimaging methods, such as fMRI, leading to more accurate interpretations of brain activity and function.