methylenedioxymethamphetamine (Ecstasy) administration in rats induces neuroadaptive changes in expressions of glutamatergic NMDA subunits, in regions of the brain regulating reward-related associative learning, cognition, and memory (Kindlundh-Hogberg et al., 2008). Grin2a (Nr2a) knockout mice exhibit retarded discrimination learning (Brigman et al., 2008). Associations were reported for GRIN2A polymorphisms with attention-deficit/hyperactivity disorder (ADHD), autism, and worse chronic outcome in schizophrenia (Adams et al., 2004, Barnby et al., 2005, Itokawa et al., 2003, Tang et al., 2006, Turic et al., 2004). The biological functions of the GRIN2A SNPs indicated in this study are unknown but the finding is supported by associations with multiple SNPs at the same gene, and by the haplotype analysis that was close to significance after correction for multiple testing.
