Abstract
The current study assessed neurotrophin protein levels in male and female rat brain tissues at four different ages ranging from postpuberty to senescence. In both sexes nerve growth factor (NGF) increased, and brain-derived neurotrophic factor (BDNF) decreased, from 4 to 24 months of age. Using a slightly older age for the young group, or a slightly younger age for the aged group, had profound effects on whether age effects were realized. There were no sex differences in the pattern of change in neurotrophin levels across age, and neurotrophin levels did not correlate with estrogen levels in females or estrogen or testosterone levels in males. The current findings suggest that profound changes in neurotrophin protein levels can occur within only a few months time, and that these changes influence whether age-related neurotrophin alterations are realized.
Acknowledgments
The authors wish to thank the Core Endocrinology Laboratory at Pennsylvania State University for performing the hormone assays. This research was funded by grants awarded to HAB-N (National Institute on Aging [AG026137 and AG026137] and to ACG (AG10755).
Notes
Note. hippo = hippocampus; ent = entorhinal; ns = not significant.