Background: Cognitive impairment is a major problem, which eventually develops in schizophrenia. It contributes to the patients’ functional disability and cannot be attenuated by antipsychotic drugs. Bacopa monnieri (Brahmi), a neuroprotective herbal medicine in the elderly, might be a novel neuroprotective agent for prevention of cognitive deficit in schizophrenia.
Objective: To study neuroprotective effects of Brahmi on novel object recognition task and cerebral glutamate/N-methyl-Daspartate receptor subtype 1 (NMDAR1) immunodensity in sub-chronic phencyclidine (PCP) rat model of schizophrenia.
Material and Method: Rats were assigned to three groups; Group-A: Control, Group-B: PCP administration and Group-
C: Brahmi + PCP. Discrimination ratio (DR) representing cognitive ability was obtained from novel object recognition task. NMDAR1 immunodensity was measured in prefrontal cortex, striatum, cornu ammonis fields 1 (CA1) and 2/3 (CA2/3) and dentate gyrus (DG) using immunohistochemistry.
Results: DR was significantly reduced in PCP group compared with control. This occurred alongside NMDAR1 up-regulation in CA2/3 and DG, but not in prefrontal cortex, striatum or CA1. Brahmi + PCP group showed an increased DR score up to normal which occurred alongside a significantly decreased NMDAR1 immunodensity in CA2/3 and DG compared with PCP group.
Conclusion: Cognitive deficit observed in rats receiving PCP was mediated by NMDAR1 up-regulation in CA2/3 and DG.
Interestingly, receiving Brahmi before PCP administration can restore this cognitive deficit by decreasing NMDAR1 in these brain areas. Therefore, Brahmi could be a novel neuroprotective agent for the prevention of cognitive deficit in schizophrenia.

Keywords: Brahmi, Schizophrenia, Animal model, Novel object recognition, NMDAR1