Italian neuroscientists are the first to discover that the maximum life span of some mammalian neurons may not be limited by the maximum life span of the organism in which they originated as reported in the Feb. 25, 2013, Proceedings of the National Academy of Science.
The scientists transplanted neuronal precursors from the developing mouse cerebellum into the cerebellum of rat embryos, using a strain of rat that can live on average nearly twice as long as the donor mouse strain.
The grafted cells developed into cerebellar neurons and integrated into the rat brains, but retained a mouse-like size and shape.
The grafted cells survived for as long as their rat hosts (up to 36 months) roughly twice as long as the average life span of the donor mice.
The findings suggest that the life span of the transplanted neurons is not genetically fixed and may have been determined by the rat brain microenvironment or other factors.
For the present, the research indicates that increasing longevity in technologically advanced societies does not necessarily doom people to neuronally depleted brains prior to death.
This research also indicates that the entire transfer of a human brain to a potential clone body could maintain the integrity of the transplant donor’s persona, memories, and “self”.