Persistent inflammatory nociceptive stimulus impact followed or not by opioid analgesia on the hippocampal neurogenesis, cell death, learning and anxiety behavior in rats

Abstract

The neonatal has been associated to neurological and behaviour long-term consequences in premature newborns although its real effects on the nervous system have been not elucidated yet. Objective: to evaluate possible consequences from pain, followed or not by analgesia on the hippocampal neurogenesis, cell death, anxiety behavior and learning in rats. Methods: this is a experimental study performed in animals, whereby the nociception will be caused by the injection of complete freund's adjuvant in the paw's subcutaneous on the first day of life, which will develop a strong inflammatory reaction. Analgesia will be performed by the daily Fentanyl intra peritoneal injections from the first up to the sixth day of life. Outcomes: Neurogenesis of the dentate gyrus of hippocampus will be evaluated by bromodeoxyuridine (BrdU) and a neuronal nuclear antigen (NeuN). Cell survival and proliferation will be assessed at young age and adulthood. Cell death: immunohistochemistry for caspase-3 and TUNEL. Learning and anxiety behavior: open field, plus maze and water maze tests in adult animals. (AU)