In vivo hemodynamic visualization of berberine-induced effect on the cerebral cortex of a mouse by photoacoustic tomography.

While berberine, a traditional Oriental herbal drug commonly used for treatment of diarrhea, has recently been used to treat a number of brain disorders, such as stroke and Alzheimer's disease, berberine-induced changes in hemodynamics are largely unknown. Here, we utilize photoacoustic tomography (PAT) to study hemodynamic effects of berberine in mice. In vivo photoacoustic images are obtained in ten functional regions of a mouse brain. Cortical vascular network and dynamic changes in total hemoglobin (HbT) concentration are acquired at 532 nm. Functional atlas and statistical data are also obtained at low-dose and high-dose berberine. Our results provide compelling evidence that both low-dose and high-dose berberine can increase the HbT concentration to a varied extent in certain brain regions. This study also suggests that PAT provides a powerful tool for visualizing brain hemodynamic changes induced by drugs.