11/15 – Douglas Rothman, Yale University
Biomedical Engineering Seminar
November 15, 2024
11:00 AM - 12:00 PM
Location
BME Seminar in SEO 236
Address
851 S Morgan St, Chicago, IL 60607
Calendar
Download iCal FileSpeaker:
Douglas Rothman, Ph.D.
Professor
Yale University, Department of Diagnostic Radiology and Biomedical Engineering
Title: In vivo functional MRS and MRI studies and homeostatic modeling reveals the relationship between neurometabolic and neurovascular coupling
Abstract: Disproportional increments in CBF and CMRO2, referred to as neurovascular coupling critical for brain function and the basis of MRI functional imaging. Traditionally it has been described as a mechanism for providing excess O2 supply to activated tissue to provide a buffer against transient hypoxia. However, studies over the last 20+ years have found that the brain has a highly restricted capillary O2 mass transfer coefficient, and therefore cannot extract the excess in O2 supplied. We alternatively propose that rather than being a mechanism for providing excess O2, it primarily is an adaptation to compensate for the large increase in non-oxidative glucose and glycogen metabolism and associated H+ production referred to as neurometabolic coupling. The talk is in three parts.
First, experimental findings from fMRI, MRS, and PET studies of neurometabolic and neurovascular coupling will be reviewed, with an emphasis on several stoichiometric relationships between signaling and neuronal and astrocytic energy requirements.
Second, a metabolic model is presented which derives experimentally observed neurometabolic coupling fluxes based on homeostatic constraints and limitations in the ability to rapidly increase CBF to the brain relative to neuronal signaling energy needs.
Third, the measured neurovascular coupling relationship between CBF and CMRO2 is derived based on the model of neurometabolic coupling and a homeostatic model that calculates blood and brain pO2, pCO2, and pH based upon the binding properties of RBC hemoglobin (Bohr and Haldane effects). Evidence for altered neurovascular coupling sufficient to lead to pathological increases in blood and brain in healthy aging is also presented.
Date posted
Nov 7, 2024
Date updated
Nov 7, 2024