References and Notes

hippocampus is still absent or low, whereas the ε2 and 1 subunits are already expressed at a high level (4, 6, 7, 23). In this case, the asymmetrical allocation of ε2 subunits may produce distinct numbers of NMDA recep-tors in these synapses, resulting in differential ability to express synaptic plasticity (Fig. 3E). Hippocampal pyramidal neurons, thus, might regulate the development of synaptic plasticity in a side-selective manner by con-trolling the synaptic allocation of ε2 subunits. The left-right asymmetry is a fundamen-tal concept of brain science (25–27). Our present findings suggest that the brain can involve asymmetries not only at a macro