Dissociable onset of cognitive and motivational dysfunctions following neonatal lesions of the ventral hippocampus in rats

Behav Neurosci. 2008 Jun;122(3):629-42. doi: 10.1037/0735-7044.122.3.629.


This research examined cognitive and motivational processes at different developmental stages in rats with neonatal ventral hippocampus (VH) lesions, an approach used to model schizophrenia. In Experiment 1, performance in a T-maze alternation task was assessed on postnatal days (PNDs) 22 and 23. VH-lesioned rats displayed a severe deficit relative to controls. In Experiment 2, behaviorally naive rats were tested for spontaneous alternation at PND 29. Alternation was intact in VH-lesioned rats only when successive alternations were separated by >5 s. In Experiment 3, motivation was tested in a cost-benefit T-maze task and in a saccharine-water preference test. Between PNDs 22-37, behaviorally naive rats with neonatal VH lesions displayed weaker saccharine preference than controls, but the 2 groups did not differ on the cost-benefit task. At adulthood, between PNDs 56-72, the difference on saccharine preference persisted and an impairment on the cost-benefit task emerged. Overall, these results suggest that working memory deficits observed at the weaning stage were not secondary to spontaneous alternation or motivation dysfunctions.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Age Factors
  • Analysis of Variance
  • Animals
  • Animals, Newborn
  • Choice Behavior / physiology
  • Cognition Disorders / pathology*
  • Cognition Disorders / physiopathology*
  • Female
  • Hippocampus / growth & development
  • Hippocampus / injuries*
  • Male
  • Maze Learning
  • Motivation*
  • Pregnancy
  • Rats
  • Rats, Sprague-Dawley
  • Reaction Time / physiology
  • Reinforcement, Psychology