NRG1 and schizophrenia: NRG1 may also participate in the pathogenesis of schizophrenia [8]; a marked increase in NRG1 signaling can be seen in the prefrontal cortex in schizophrenia and, moreover, NRG1 stimulation suppresses N-methyl-D-aspartate (NMDA) receptors (a family of L-glutamate receptors that play an important role in learning and memory) in the human prefrontal cortex in schizophrenia and in schizophrenic brain models [42].