EMBO J 31 4, 805–816 (2012); published online December 20 2011
Synaptic plasticity, the activity-dependent modification of synaptic strength, plays a fundamental role in learning and memory as well as in developmental maturation of neuronal circuitry. However, how synaptic plasticity is induced and regulated remains poorly understood. In this issue of The EMBO Journal, Yang and colleagues present sets of exciting data, suggesting that G-protein-coupled receptors (GPCRs) selectively execute distinct signalling pathways to differentially regulate induction thresholds of hippocampal long-term potentiation (LTP) and long-term depression (LTD), thereby governing the direction of synaptic plasticity. These results shed significant light on our current understanding of how bidirectional synaptic plasticity is regulated.