Kinetic Modeling of the Blood Oxygenation Level Dependent (BOLD) Signals and Biocatalytic Reactions Observed in the Human Brain Using MRI: An Analysis of Normal and Pathological Conditions

• Published in: ACS chemical neuroscience Vol. 11; no. 5; pp. 763 - 771
• Main Authors: Varfolomeev, Sergey D, Bykov, Valeriy I, Semenova, Nataliya A, Tsybenova, Svetlana B
• Format: Journal Article
• Language: English
• Published: United States American Chemical Society 04.03.2020
• Subjects: fMRI; dynamic process; schizophrenia; kinetic model; BOLD signal; N-acetylaspartate
• ISSN: 1948-7193; 1948-7193
• DOI: 10.1021/acschemneuro.9b00671

A kinetic model describing the pulse of increased oxygen concentrations and the subsequent changes in the concentration of N-acetylaspartate in the excited nervous tissue of the human brain in response to an external signal is presented. The model is based on biochemical data, a multistage and nonlinear dynamic process the BOLD signal and N-acetylaspartate. The existence of multiple steady states explains the triggering effect of the system. The inhibitory effect of the substrate is a necessary factor for the autostabilization of N-acetylaspartate. The kinetic model allows the dynamic behavior of previously unmeasurable metabolites, namely, products of the hydrolysis of N-acetylaspartate, such as acetic and aspartic acid, and glutamic acid to be predicted. Kinetic modeling of the BOLD signal and the subsequent hydrolysis of N-acetylaspartate provides information about the biochemical and dynamic characteristics of some pathological conditions (schizophrenia, Canavan disease, and the superexcitation of the neural network).