Functional imaging of olfactory bulb and somatosensory cortex in mice using small-animal blood flow imaging platform

Abstract

A portable, compact and modular small-animal imaging platform is designed for measurement of deep tissue and superficial cerebral blood flow. The platform is integrated with optics, data acquisition unit, display unit and on-board single-board computer (SBC) that supports a Graphical User Interface (GUI). It also contains a customizable stereotaxic frame for both mice and rats for housing the animals along with provision for anesthesia, pulse oximeters and temperature probes. Functional studies have been conducted in the olfactory bulb and somatosensory cortex in mice brain using the imaging platform to measure relative cerebral blood flow (rCBF). We show longitudinal blood flow changes in the pre-cortical brain region associated with multiple odours, categorized broadly into ester, phenyl propanoid and terpenoids chemical group. A forepaw stimulation study has also been conducted to show blood flow changes in the cortical region of the brain. The surface as well as depth-wise blood flow changes due to the stimulations have been shown using Laser Speckle Contrast Imaging (LSCI) and Multi-speckle Diffuse Correlation Tomography (M-DCT) respectively.