Simone Claudia Bosshard1, Christof Baltes1, Hanns Ulrich Zeilhofer2, Markus Rudin1,2
1Institute for Biomedical Engineering, ETH and University of Zurich, Zurich, Switzerland; 2Institute of Pharmacology and Toxicology, University of Zurich, Zurich, Switzerland
Effects of the local anesthetic Lidocaine on the BOLD signal in the somatosensory cortices and the thalamus of mice following electrical stimulation of the forepaw have been studied. Pretreatment of the stimulated forepaw with low concentrations of Lidocaine led to an increased BOLD response in the corresponding brain areas, in line with increased sensitivity observed in behavioral tests, indicating a hyperalgesic effect of Lidocaine on the C-type sensory afferents which process noxious stimuli. High concentration of Lidocaine abolished the BOLD response after electrical stimulation. This approach potentially allows distinguishing noxious from innocuous stimuli using BOLD fMRI in mice.