Guilfoyle Lab

The main goals of Dr. Guilfoyle’s Biophysics Lab are: a basic science approach to MR diffusion, and spectroscopy measures to further characterize the cellular activity responsible for the observed signal changes.


Many studies in neuroscience compare a control group to a patient group. This is true of functional MRI (resting state or task driven), and diffusion tensor imaging, the main MR modalities currently used. Regional differences are detected, and this provides valuable information about the disorder. Our focus is to try to determine the cellular activity which is responsible for the differences observed between patients and the matched control groups. For example, the BOLD response measured with fMRI is based on a transient increase in the ratio of oxyhemoglobin to deoxyhemoglobin which in turn is based on changes in cerebral blood flow (CBF). This is used as a proxy for changes in neuronal activity. However, the mechanisms by which neurons rapidly communicate with the vascular system remains unclear. The study of these neurovascular coupling mechanisms is one of the prime goals of our group.

DTI has proved very successful in measuring white matter microstructure abnormalities. Combining diffusion measures with other modalities and mathematical modeling of diffusion will lead to a more meaningful interpretation of signal changes.

Current Investigations

Development of the dwell-time diffusion theory, which explains how the presence of dead-end pores within the extracellular space (ECS) impacts its diffusion properties, and generalization of the diffusion equation for inhomogeneous porous environments.
The role of astrocytes in neurovascular coupling mechanisms.