Although we have nerves throughout the body, a person's essential personality and memories are thought to be stored more or less completely in the brain. In theory, you could transplant a brain into a new body, and the individual who would awaken would be the one whose brain is used. It would be more of a "body transplant", in a sense. This has the interesting consequence that an individual could be preserved after multiple organ failures, if only their brain could be prevented from losing its memories irrecoverably at the moment of death, and transitioned to a stable state. Even if the preservation mechanism were to turn the brain into a completely inert substance devoid of ongoing consciousness, the hope of reanimating them and restoring consciousness would remain for as long as scientific progress continues and their storage is maintained. There are several general approaches to rendering living tissue inert over a long period of time: plastination, dehydration, and cryopreservation. Although human cells can tolerate dessication under some conditions (http://www.ncbi.nlm.nih.gov/pubmed/11578120), this is unlikely to translate to organized brain tissue. Not only would there be extreme morphological distortion and cytostructural damage, the concentration of proteins within cells in the absence of protective sugars like trehalose tends to be harmful. Lyophilization (freeze drying) has similar problems, although it is not as harmful. Plastination (replacing the water with a resin or plastic that solidifies at a higher temperature) for EM tends to rely on formalin fixation, which renders cells nonviable. So we would have to be very confident that we can make use of the raw morphological data, if this approach were to be used on a living patient. More problematically, fixing and plastinating something as large as the brain has never been done successfully. Cryopreservation has problems as well. If low concentrations of cryoprotectants are used, ice tends to form, as heat cannot be removed from a large organ like the brain fast enough for supercooling to the glass transition temperature. High concentrations must be used instead. This renders cells nonviable, given realistic cooling times. Nonetheless, it does provide a route to morphological preservation (considered the current best case scenario in cryonics). Some progress has been achieved in reducing the toxicity of cryoprotectants, and reducing the concentration required. The osmolar concentration is what determines freezing point depression, however cooling below the freezing point is possible to some degree. Ice blockers can be used for this. The tissue being vitrified may also be placed under high hydrostatic pressure as a way to prevent ice formation. In 2004 a rabbit kidney was reversibly vitrified, and implanted successfully. (http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2781097/) It seems strange to me that there are not more people interested in neural cryobiology, particularly the effects of high-osmolality vitrification. It seems that most interest in this is fueled by cryonics/transhumanism in some fashion, e.g. the Brain Preservation Foundation prize. Nonetheless, it is an empirical field where observations regarding viability and morphological preservation can be made.