Brain cells can live at least twice as long as the organisms in which they reside, according to new research. The study, published today (Feb. 25) in the journal Proceedings of the National Academy of Sciences, found that mouse neurons, or brain cells, implanted into rats can survive with the rats into old age, twice as long as the life span of the original mice.
The brain contains some 100 billion nerve cells called neurons (Figure 1, to the rightsynapses) which branch out to form over one quadrillion connections called synapses. (Figure 2, to the left). The easiest way trading brainto conceptualize this is that there are more synapses in the human brain than there are stars in the known universe. Memory and learning occur when the neurons and synapses reorganize and strengthen themselves through repeated usage.