Synaptic Ménage à Trois

Regulation of neurotransmitter receptorlocalization is critical for synaptic function and plasticity. In this issue of Neuron , Matsuda and colleagues (Matsuda et al., 2016) uncover a transsynaptic complex consisting of neurexin-3, C1q-like proteins, and kainate receptorsthat drives glutamate receptorclustering at hippocampal synapses.