GPR139 and schizophrenia: A small molecule agonist was developed to test whether these deficits are reversible; it was tested in vivo in social interaction in poly (I:C) and cognitive tests in subchronic PCP models of schizophrenia, and it was observed to reverse these deficits, implying that GPR-139 expression plays a protective role in the development of negative symptoms in schizophrenia [26].