NCAM1 and schizophrenia: Acute stress leads to reductions in both the quantity and quality of polySia in the olfactory bulb and prefrontal cortex [35], and treatment with anti-schizophrenia agents can consistently upregulate the expression of polySia in the PFC [36], a location in which altered polySia-NCAM expression has been observed in schizophrenia patients [37].