Perinatal asphyxia induces neurogenesis in hippocampus: an organotypic culture study.
There is clinical and experimental evidence indicating that neurocircuitries of the hippocampus are vulnerable to hypoxia/ischemia occurring at birth, inducing, upon re-oxygenation/re-circulation, delayed neuronal death, but also compensatory mechanisms, including neurogenesis. In the present report, perinatal asphyxia was induced by immersing foetuses-containing uterine horns removed from ready-to-deliver rats into a water bath at 37 degrees C for 20 min. Some pups were delivered immediately after the hysterectomy to be used as non-asphyxiated caesarean-delivered controls. The pups were sacrificed after seven days for preparing organotypic hippocampal cultures. The cultures were grown on a coverslip in a medium-containing culture tube inserted in a hole of a roller device standing on the internal area of a cell incubator at 35 degrees C, 10% CO2. At days in vitro (DIV) 25-27, cultures were fixed for assaying cell proliferation and neuronal phenotype with antibodies against 5-bromo-2'deoxyuridine (BrdU) and microtubule associated protein-2 (MAP-2), respectively. Confocal microscopy revealed that there was a 2-fold increase of BrdU-positive, but a 40% decrease of MAP-2-positive cells/mm3 in cultures from asphyxia-exposed, compared to that from control animals. Approximately 30% of BrdU-positive cells were also positive for MAP-2 (approximately 4800 cells), mainly seen in the dentate gyrus of the hippocampus, demonstrating a 3-fold increase of postnatal neurogenesis, when the total amount of double-labelled cells seen in cultures from asphyxia-exposed animals is compared to that from control animals.
Morales
P
P
Programme of Molecular and Clinical Pharmacology, ICBM, Medical Faculty and Department of Biochemistry and Molecular Biology, Chemical and Pharmaceutical Sciences Faculty, University of Chile, Santiago, Chile.
Huaiquín
P
P
Bustamante
D
D
Fiedler
J
J
Herrera-Marschitz
M
M
D000818:Animals; D000831:Animals, Newborn; D001237:Asphyxia / Q000503:physiopathology*; D006624:Hippocampus / Q000503:physiopathology*; D009474:Neurons / Q000166:cytology / Q000502:physiology*; D009924:Organ Culture Techniques; D010749:Phosphoprotein Phosphatases / Q000187:drug effects / Q000378:metabolism; D051381:Rats
C049301:microtubule-associated protein-2 phosphatase; D010749:Phosphoprotein Phosphatases