The impact of paternal PTSD-like stress on cognitive behavior and hippocampal BDNF expression in adolescent male and female rat offspring: modulatory effects of lithium

Prenatal stress may lead to cognitive and behavioral dysfunction in the offspring. Large evidence has shown the deleterious effects of maternal stress on cognitive and behavioral functions of the offspring; however, the effect of paternal stress has not been well documented. In the present study, we aimed to investigate the effect of paternal stress (chronic electrical footshocks, post-traumatic stress disorder or PTSD-like model) on cognitive and behavioral functions, and brain-derived neurotrophic factor (BDNF) hippocampal level in both male and female offspring during adolescence. The father rat (stress-exposed) was exposed to three consecutive shocks in a fear conditioning apparatus for ten times during four weeks, in an uncertain and unpredictable schedule. Saline (0.5 mL) or lithium chloride (50 mg/kg) was intraperitoneally injected to male and female offspring during 21-41 postnatal day (PND). The results showed that paternal stress decreased locomotor activity in female offspring, and increased anxiety-like behavior in both male and female offspring, with more effect on females. Paternal stress also decreased pain subthreshold only in female offspring and impaired passive avoidance and spatial memory in both male and female offspring. Paternal stress also decreased BDNF expression level only in female offspring. However, lithium reversed most of the behavioral dysfunctions in rats' offspring with a history of paternal stress. We concluded that paternal stress significantly impairs cognitive and behavioral function in the offspring during adolescence, with more effect on females. Also, chronic lithium treatment may reverse the deleterious effects of paternal stress.