fMRI in rodents has become a widely used technique with various applications in preclinical research. In this context, most studies are performed with anesthetized animals. Medetomidine evolves as a frequently used sedative but long term stability is limited -prolonged stability can be achieved by addition of Isoflurane. Several recent fMRI studies have used this combination. We evaluated the effects of this combination of anesthetics using a multimodal setup of BOLD fMRI and Ca2+ recordings. Even small addition of Isoflurane resulted in a significant decrease of neural (Ca2+) and hemodynamic (BOLD) responses to a distinct electrical stimulus.