DLG4 and psychiatric disorder: Gene expression analysis also identified synaptic structure and function as a key difference between SGCEwt and SGCEko lines, also implicated in other genetic forms of dystonia, and other neurological and psychiatric disorders.36,42 A simplified schematic illustration of a cortical excitatory glutamatergic synapse (Fig. 7A) outlines the multiple components that contribute to its function, with these including synaptic proteins (synapsin, PSD95, VGLUT1), receptors (AMPA, NMDA) and adhesion molecules (neurexin, neuroligin).