Neurotrophins in neonatal hypoxic-ischemic encephalopathy

Abstract

Aims The aims of this study are to investigate the alteration in the expression of brain-derived neurotrophic factor and neurotrophin 3 and their receptors, both the full length functional forms and the truncated forms, in neonatal mouse brain subjected to hypoxic-ischemic insult. Materials and Methods In order to produce a reliable model of neonatal hypoxic-ischemic insult, seven days old mice were subjected to the unilateral ligation of the common carotid artery and subsequent exposure to 8% oxygen and 92% nitrogen for 30 minutes. Results This animal model has a very high reliability in producing repeatable damage. The focal damage mainly involved the brain regions supported by the medial cerebral artery. Eosinophilic and condensed pyknotic cells were common in the pyramidal layer of the CAl, CA2 and CA3 regions of the hippocampus. Necrotic changes of other regions, such as the cortex, or the CAl region of the hippocampus were also occasionally observed. Conclusion The establishment of this model permits the use of in situ hybridization and reverse transcription polymerase chain reaction (RT-PCR) to identify the changes of molecular expression of neurotrophins and their receptors in hypoxic-ischemic encephalopathy. Currently, our effort is directed at optimizing the hybridization conditions for various molecular probes and the isolation of RNA from different brain regions for RT-PCR study.