Pioglitazone attenuates behavioral and electrophysiological dysfunctions induced by two-hit model of schizophrenia in adult rodent offspring

Abstract

Maternal infection and stress exposure, especially during childhood and adolescence, have been implicated as risk factors for schizophrenia. Both insults induce an exacerbated inflammatory response, which could mediate disturbance of neurodevelopmental processes and, ultimately, malfunctioning of neural systems observed in this disorder. Thus, anti-inflammatory drugs, such as PPARγ agonists, may potentially be used to prevent the development of schizophrenia. Microglia culture was prepared from the offspring of saline or poly(I:C)-injected mice. The cells were pretreated with pioglitazone and then, stimulated by LPS. Proinflammatory mediators and phagocytic activity were measured. Also, pregnant rats were injected with saline or poly(I:C) on GD17. The offspring were subjected to footshock during adolescence and subsequently injected with pioglitazone or vehicle. At adulthood, behavior and dopaminergic activity were evaluated. Pioglitazone reduced proinflammatory mediators induced by poly(I:C) microglia stimulated by LPS without affecting their decreased phagocytic activity. The PPARγ agonist also prevented the emergence of social and cognitive impairments, as well as attenuated the increased number of spontaneously active dopamine neurons in the VTA, observed in both males and females from poly(I:C) and stress group. Therefore, pioglitazone could potentially prevent the emergence of the schizophrenia-like alterations induced by the two-hit model via reduction of microglial activation.

Keywords: Behavioral impairments; Dopamine; Maternal immune activation; PPARγ agonist; Schizophrenia; Stress.