MRI sensor to detect calcium activity within neuronsMay 8, 2019
Ali Barandov et al developed a novel magnetic resonance image (MRI) based sensor that can detect calcium activity within neurons, allowing them to closely track brain activity. Calcium ions are essential in signal transduction in almost all cells including neurons. Measuring calcium concentration requires the need for an effective contrast agent that can allow for their accurate detection. The researchers thus developed a manganese-based paramagnetic contrast agent, ManICS1-AM, that is designed for easy permeation through the cell membrane. The contrast agent contains a manganese part that interacts weakly with magnetic fields. It also contains a calcium-binding arm called a chelator. Calcium levels were detected based on their binding activity with the chelator, which shields or exposes the manganese atom for MRI detection accordingly. This helps make the contrast agent appear brighter during imaging. The researchers tested the sensor in rats by injecting it into the striatum. Electrical activity was stimulated in the neurons of the striatum and the calcium response in the cells were measured. The study thus demonstrates a cell-permeable manganese-based MRI contrast agent that can help detect signaling events in deep tissue using MRI which can be utilized for a variety of applications in basic biology and biomedicine.
Source: Nature Communications February 22, 2019 volume 10, Article number: 897 (2019)