| Research Abstract |
We have established sensitive tow-site enzyme immunoassay systems for neurotrophin-3 (NT-3) and brain-derived neurotrophic factor (BDNF), in addition to nerve growth factor, and have shown that our immunoassay systems quantify BDFN and NT-3 with their molecular mass of 13 kDa and 14 kDa, respectively. Then, weinvestigated a regional distribution of BDNF and NT-3, and developmental changes in their levels in the brain and selected tissues from rats. Appreciable levels of BDNF was found in the olfactory bulb, septum, hippocampus, striatum, cerebral cortex, cerebellum and hypothalamus from rats at one month of age. By contrast, fairly high concentrations of NT-3 were found only in four regions from the same aged rats, such as the hippocampus, septum, cerebellum and olfactory bulb. The highest concentrations of BDNF and NT-3 were observed in the hippocampus (5.41 and 42.0ng/g, respectively). Highlevels of NT-3 were detected in the visceraltargets of the nodese ganglia while very low levels of BDNF was detected in the spleen, thyumus, hypophysis and liver, but not in other peripheral tissues. The concentration of BDNF increased during the first 30 postnatal days in all brain regions. Levels of NT-3 incressed in the olfactory bulb, hippocampus and septum during the first 60 days of age while they decreased in the cerebelum and secebral cortex. These observations seem to support the consideration that BDNF functions in adulthood and NT-3 does so in embryonic and neonatal periods. Immunocytochemical analyzes showed that NT-3 was lozalized in the CA-2-CA4 regions of teh pyramidal cell layr and BDNF was localized in the nucleus of some granule cells in the dentate gyrus and of a few neurons in the pyramidal cell layr and in the hypothalamus.
|
