In a vote for coolest experiment of the year, scientists at
Stanford University surgically created conjoined-twin mice of
different age pairs to assess the impact of young versus old
blood on the brain. Published this month in Nature, researchers
investigated the effect of proteins in the blood to encourage or
inhibit neurogenesis (new cell growth in the brain),
concentrating on the dentate gyrus of the hippocampus, a key
area in memory consolidation and a region known to be
susceptible to environmental and age-related changes in cellular
growth and death. The hippocampus is strategically located in an
area rich with blood vessels, making it an ideal region to look
for the effects of aging blood on the brain. First, looking at
older mice, scientists identified a decrease in neurogenesis and
synaptic plasticity, as well as behavioral learning and memory,
confirming deficits commonly seen in aging populations. Next,
using a procedure called parabiosis, pairs of young and old mice
were surgically attached to one