Exp Biol Med (Maywood). 2003 Jul;228(7):800-10.
A dietary supplement abolishes age-related cognitive decline in
transgenic mice expressing elevated free radical processes.
We previously found that transgenic mice overexpressing growth
hormone (TGM) have elevated and progressively increasing free radical
processes in brain that strongly correlates with reduced survivorship.
Young mature TGM, however, displayed vastly enhanced learning of an
eight-choice cued maze and qualitatively different learning curves than
normal controls. Here we document the age-related patterns in learning
ability of TGM and normal mice. Learning appeared inferior in both
genotypes of very young mice but TGM were confirmed to be superior to
normal mice upon maturity. Older TGM, however, showed rapid age-related
loss of their exceptional learning, whereas normal mice at 1 year of age
showed little change. The cognitive decline of TGM was abolished by a
complex "anti-aging" dietary supplement formulated to promote membrane
and mitochondrial integrity, increase insulin sensitivity, reduce reactive
oxygen and nitrogen species, and ameliorate inflammation. Results are
discussed in the context of reactive oxygen and nitrogen species,
long-term potentiation, learning, aging and neuropathology, based on
known impacts of the growth hormone axis on the brain, and
characteristics of TGM.
Comment by poster:
Old treated TGM exhibited even greater learning ability than young TGM.