GRIN2B and schizophrenia: However, there are two caveats to these observations: firstly, on the one hand, some deficits seen after ablation of Grin1 or Grin2B in excitatory cells (Table 2) may be difficult to reconcile with the symptom-profile of schizophrenia, including a wide range of deficits in basic long-term associative spatial memory tasks, fear extinction and cue-discrimination in fear-conditioning, as well as enhanced social memory (188, 226, 229, 231).