This book studies the cell aging of individual animals as observed by light and electron microscopic radioautography. Also discussed in this compilation is sarcopenia, which is the age-related loss of skeletal muscle mass, as well as recent advances in basic molecular mechanisms that underlie aging with findings that are shedding light on the pathogenesis of Alzheimer's disease. The authors also study Akt/protein kinase B (PKB), which plays a prominent role in the regulation of cellular homeostasis including cell survival, cell growth and gene expression; and, understanding the process and mechanisms involved in erythrocyte senescence.