Here is a very interesting article in Nature which takes a look at adult neurogenesis with respect to blood proteins. The researchers demonstrated a link between age-related molecular changes in the blood and the decline in synaptic plasticity and cognitive function associated with ageing. Using a technique called heterochronic parabiosis, they found that young mice which were sharing a systemic environment with older mice experienced cellular and cognitive changes similar to that of aged mice. Of particular note, the investigators found a correlation between the reduced neurogenesis and levels of several chemokines present in the plasma.
