Whilst hippocampal kainate receptor levels are reportedly unchanged in schizophrenia (Noga and Wang, 2002; Beneyto et al., 2007), decreased GluR6 and KA2 mRNA expression has been reported in some (Porter et al., 1997) but not all (Beneyto et al., 2007) studies, suggesting that the composition of kainate receptors may also be altered in some people with the disorder. Here, GRIK5 is linked to schizophrenia.