Phosphoinositide dynamics in the postsynaptic membrane compartment: Mechanisms and experimental approach

Phosphoinositides (PIs) are minor constituents of eukaryotic membranes that control a plethora of cellular functions through direct modulation of membrane-associated proteins and through membrane recruitment of enzymes or signaling molecules. It is well established that in neurons PIs play essential roles in the pre-synapse, especially during exocytotic neurotransmitter release and recycling of synaptic vesicles. In contrast, the physiological importance of PIs in postsynaptic membranes is far less understood. The extent and the spatiotemporal characteristics of dynamic changes in the concentrations of PIs caused by synaptic activity are largely unknown. Recent work suggests that postsynaptic PI dynamics are involved in the induction and maintenance of synaptic plasticity, but the general principles are far from clear. This review summarizes current knowledge on the relevance of PIs for postsynaptic processes, focussing on PI signaling in the control of electrical activity and synaptic plasticity. We highlight the state-of-the-art of methods to study PI dynamics and discuss recent technical improvements that should help to define the role of PIs in postsynaptic physiology.