Chronic melatonin treatment reverses disruption of prepulse inhibition in pinealectomized and pinealectomized-plus-ovariectomized rats

► Prepulse inhibition (PPI) was disrupted in pinealectomized (Px) and pinealectomized-plus-ovariectomized (Px + Ovx) rats. ► Chronic melatoin treatment reversed the impairments of PPI induced by Px or Px + Ovx. ► Novel object recognition and passive avoidance tests were not affected by chronic melatonin treatment. ► Melatonin increased the locomotor activity of Px and Px + Ovx rats, but reversed the locomotor hyperactivity caused by Ovx. ► Chronic melatonin treatment may be useful in the disorders characterized by PPI disruption.