Effect of prenatal haloperidol exposure on behavioral alterations in rats

Pregnant Charles-Foster rats were exposed to haloperidol (HAL), a neuroleptic drug that binds to and blocks dopamine (DA) receptor subtypes at a dose of 2.5 mg/kg body weight (intraperitoneally) from Gestation Day (GD) 12 to 20. The animals from both treated as well as vehicle control groups were allowed to deliver on GD 21. The offspring culled at birth on the basis of sex and weight were subjected to behavioral tests at the age of 8 weeks. The HAL-treated rat offspring showed a significant increase in anxiogenic behavior on the open field, elevated plus-maze and elevated zero-maze tests when compared with the vehicle-treated (control) rat offspring of the same age group. These findings suggest that prenatal exposure to HAL during a critical period of brain development leaves a lasting imprint on the brain, resulting in abnormal anxiety states, possibly through dopaminergic neurotransmission mechanisms.