Electrical activity of neurones is associated with calcium influx through various channels. Most neurones extrude this calcium very rapidly on the plasma-membrane calcium pump (PMCA). Our research shows that this extrusion occurs in exchange for hydrogen ions, resulting in an intracellular acidification. We believe that this causes a significant and important local pH change which shapes the activity of local proteins. Disorders, such as P/Q-type channelopathies support this hypothesis since they arise from reduced calcium fluxes and can be treated by making pH shifts larger. Currently we are using the flash release of acid inside neurones to look at the effect of acid transients on local neuronal function. We have two confocal microscopes and associated electrophysiology rigs. Projects cover a range of model systems from Drosophila larva neuromuscular junctions, through snail neurones through to rat Purkinje and cortical neurones.