Berlin, S. et al. eLife 5, e12040 (2016).

Synaptic strength is regulated by a family of ionotropic glutamate receptors, the NMDA receptors. To unravel the function of NMDA receptors in synaptic plasticity and transmission, Berlin et al. developed photoswitchable versions of individual NMDA receptor subunits. These LiGluNs consist of NMDA receptor subunits harboring a cysteine modification close to the ligand binding site, and a photoswitched tethered ligand that attaches to the introduced cysteine and acts as an agonist or an antagonist, depending on the configuration. The researchers generated light-activated GluN2A and GluN2B subunits as well as light-inhibited GluN2A and GluN1a subunits and demonstrated their applications in rat hippocampal cell cultures, mouse organotypic brain slices and zebrafish larvae.