Neonatal ventral hippocampal lesions disrupt set-shifting ability in adult rats.

Set-shifting in a T-maze task was assessed in rats with a neonatal ventral hippocampal lesion (NVHL), a proposed animal model of schizophrenia. NVHL animals tested as adults were impaired in shifting to a new rule; an increase in perseverative errors suggested that this impairment stemmed from an inability to suppress the previously learned strategy. The NVHL animals' performance is reminiscent of humans with prefrontal damage and patients with schizophrenia.