Decisive mechanism for selectively inducing NMDAR-dependent LTP versus LTD: The role of Ca2+ influx


  • Kim Hoffmann


Long-term potentiation (LTP) and long-term depression (LTD) are two types of synaptic plasticity. Interestingly, NMDAR-dependent LTP and LTD are induced by Ca2+ influx into the post-synaptic cell. This raises the question how the cell selectively induces either LTP or LTD. Early research suggested Ca2+ amplitude as a decisive mechanism. This essay critically evaluates this hypothesis by reviewing evidence and alternative candidates (i.e., timing/location of Ca2+ influx, NMDAR subunits, competition between AMPAR exocytosis/endocytosis). In sum, the amplitude of Ca2+ influx should be seen as one of many components entailed in the complex decisive machinery for selective LTP and LTD induction.