Altered reward sensitivity in female offspring of cocaine-exposed fathers
Recent rodent studies have demonstrated that parental cocaine exposure can influence offspring behavior, supporting the idea that environmental insults can impact subsequent generations. However, studies on the effects of paternal cocaine exposure are limited and multiple inconsistencies exist. In the current study, we behaviorally characterize the effects of paternal cocaine exposure in a C57BL/6J intergenerational mouse model. Male sires were administered cocaine hydrochloride (20 mg/kg) or saline (0.01 mL/g) once a day for 75 days, and bred with drug naïve females twenty-four hours after the final injection. Offspring, separated by sex, were tested in a battery of behaviors. We found that paternal cocaine exposure altered sensitivity to the rewarding and stimulant effects of psychostimulants and natural reward (sucrose) in female offspring; female cocaine-sired offspring showed blunted cocaine preference using cocaine conditioned place preference (CPP) at a low dose (5 mg/kg), but displayed similar preference at a higher dose (10 mg/kg) compared to saline-sired controls. Additionally, cocaine-sired female offspring exhibited higher psychomotor sensitivity to cocaine (10 mg/kg) and amphetamine (2 mg/kg) and consumed more sucrose. Cocaine-sired males exhibited increased psychomotor effects of cocaine and amphetamine. Male offspring also displayed an anxiety-like phenotype. No effect of paternal cocaine exposure was observed on depressive-like, learning and memory or social behavior in male or female offspring. Collectively, our findings show that paternal, chronic cocaine exposure induces intergenerational behavioral effects in male and female offspring with greatest impact on sensitivity to psychostimulants and sucrose in females.