Rebekka Bernard

My research focuses on:

• Neurovascular coupling (NVC)
• Hemodynamic and vascular activity in the brain and, in particular,
• The physiological causes and mechanisms of the BOLD (blood oxygen level dependent) signal

The fMRI BOLD signal is an essential measure for hemodynamic and metabolic activity in the brain and thanks to neurovascular coupling processes, an indirect measure of neuronal activity. But for its accurate interpretation it is important to understand the detailed mechanisms and processes which generate the BOLD signal.

Using simultaneous Intrinsic Optical Imaging (IOI) and ultra-high field fMRI we can measure and monitor hemodynamic activity on a microscopic single vessel level and on a macroscopic level of whole brain areas. By spatially and temporally combining Intrinsic Optical Imaging and ultra-high field fMRI methods we can utilize the good temporal and spatial resolution of IOI and the good and non-invasive accessibility of almost all brain regions with MRI. Combining and comparing the acquired information from single vessels about blood oxy- and deoxygenation, cerebral blood volume (CBV) and blood flow (CBF) and the blood oxygen level dependent (BOLD) signal from whole brain areas enables us to study various components and aspects of brain hemodynamics and from the generated signals.