2. Functional MRI via non-BOLD mechanisms
The success of functional-MRI (fMRI) stems from its ability to portray active brain regions upon prescribing a specific task. However, fMRI relies on the Blood-Oxygenation-Level-Dependent (BOLD) mechanism, which is a surrogate marker for neural activity via neurovasculature couplings. A major goal of the Lab will therefore be to harness MRI’s versatility – especially at the ultrahigh fields – towards capturing signatures for neural activity more directly. Specifically, we are interested in detecting cellular swellings upon activation, as well as neurotransmitter releases in the activated regions. Both phenomena can be considered epitomes of neural activity, and their direct detection is expected to provide much insight into the nature of the ensuing activity. We are investigating these phenomena – as well as BOLD neurophysiology – via MRI coupled to orthogonal modalities such as optical microscopy and optogenetics, in numerous settings from organotypic cultures (where hemodynamics are absent) to in vivo rodents.