Research paperCorrelation of hemodynamic and fluorescence signals under resting state conditions in mice's barrel field cortex

•A bimodal IOI-calcium imaging system was used to record resting state activity.•Neuronal and glial parts of fluorescence signal were retrieved with frequency filters.•Hemodynamic response and fluorescence signals correlation was computed.•Differences in correlation patterns were found between high and low spectrum.

Both neurons and astrocytes are known to affect local vascular response in the brain following neuronal activity. In order to differentiate the contributions of each cell type to the hemodynamic response during stimulation and resting state, intrinsic optical signal (IOI) was recorded synchronized with fluorescence imaging of calcium concentration sensitive dye Oregon Green BAPTA-1 AM. By changing the stimulation parameters (frequency and duration), it was possible to individually promote neuronal and glial responses and to compare them to levels of oxy (HbO), deoxy (HbR) and total (HbT) hemoglobin concentrations. Finally, resting state recordings were done to investigate the possible correlation between hemoglobin fluctuation and calcium transients, based on different frequency bands associated either with neuronal or glial activity.