Acetylcholine dynamics in cortical networks by an ion image sensor with neurotransmitter-sensitive magnetic nanomachines

To investigate the secretory properties in the neuronal networks, we developed the ion image sensor-based acetylcholine (ACh) imaging system utilizing with the ACh esterase-tagged magnet bead complexes. The magnetic particles were successfully placed only at the well of each sensing area of an ion image sensor (128 × 128 pixels type, 23 μm pixel pitch). The pH value decreased immediately after the addition of ACh in the medium, and the degree of pH decrease was dependent on the dose of ACh. The ACh-dependent pH decrease was also detectable in the neurons of the cortical slice stimulated with glutamate. The newly developed chemical microscopy demonstrated the 2D real-time analysis of the ACh release in the non-labelled neurons of the brain network.