1.A.10.1.34
 Glutamate receptor, ionotropic, delta-1, GRID1or GluD1, of 1009 aas and 5 or 6 TMSs in a 1 or 2 TMSs (N-terminus) + 2 or 3 TMSs + 1 TMS (C-terminus) arrangement. GluD1 is a signal transduction device disguised as an ionotropic receptor (Dai et al. 2021). GABA rather than L-glutamate acts as an excitatory neurotransmitter at many synapses in the central nervous system. Delta glutamate receptors have been reported to be functional glycine- and serine-gated cation channels in situ (Carrillo et al. 2021). Clinical features, functional consequences, and rescue pharmacology of missense GRID1 and GRID2 human variants have been described (Allen et al. 2023). GluD1 binds GABA and controls inhibitory plasticity (Piot et al. 2023). Fast synaptic neurotransmission in the vertebrate central nervous system relies primarily on ionotropic glutamate receptors (iGluRs), which drive neuronal excitation, and type A γ-aminobutyric acid receptors (GABA_ARs), which are responsible for neuronal inhibition. The GluD1 receptor, an iGluR family member, is present at both excitatory and inhibitory synapses. GluD1 binds GABA, and activation produces long-lasting enhancement of GABAergic synaptic currents in the adult mouse hippocampus through a non-ionotropic mechanism that is dependent on trans-synaptic anchoring. The identification of GluD1 as a GABA receptor that controls inhibitory synaptic plasticitywas reported by Piot et al. 2023.