Quantitative fMRI studies in rats during non-chemically based hypotension
Sanganahalli B, Herman P, Hyder F, Eke A
BOLD changes are commonly used for studying functional brain activity. Data on how systemic physiological changes (e.g., arteria blood pressure, ABP) modify the BOLD response are needed. The change of the BOLD response to stimulation in steps of non-invasively induced arterial hypotension was studied. The BOLD response did not change down to ~80 mmHg of ABP. Below this ABP the BOLD response became significantly higher than the control response. Hence ABP can influence the BOLD response. Consequently the BOLD response alone cannot be used to accurately monitor function in experiments when ABP drops below the threshold of CBF autoregulation.