The neuregulin 1 gene (Nrg1) has been implicated in schizophrenia. Nrg1 has a role in the expression and activation of neurotransmitter receptors, including the NMDA, GABA, and acetylcholine receptors [171, 210], and is relevant to several schizophrenia-related neurodevelopmental processes (reviewed in [163]). A number of studies have identified associations between Nrg1 haplotypes and schizophrenia in various populations [53, 101, 164, 198, 208–210]. Heterozygous deletion of Nrg1 has been shown to increase sensitivity of mice to the behavioral effects of cannabinoids, especially under conditions of stress [25, 26]. These mice also showed greater increases in prepulse inhibition (PPI), a marker for sensorimotor gating known to be impaired in schizophrenia, following Δ9-THC administration [25].
