Anesthesia differentially modulates neuronal and vascular contributions to the BOLD signal.

Most studies involving BOLD fMRI in basic neuroscience research are conducted with anesthetized animals. This study investigates neural and hemodynamic activity through a combination of experiments comprising BOLD fMRI, optical calcium recordings and ASL in vivo. Patch clamp experiments of neurons were conducted to evaluate electrophysiological correlates of neural activity in vitro. Various anesthetic conditions embracing numerous anesthetic depths evoked by different concentrations of isoflurane (ISO) and different degrees of hypercapnia under a constant stimulus were investigated. We observed that different anesthetic conditions had major impact on the results obtained, particularly that anesthesia could cause a massive divergence of different experimental modalities.