A) General Injury
- All brains undergo neuroplasticity in response to damage. Neurons are one of the few cells in the body that do not replicate. When they are exposed to damaging ions (e.g. free radicals) following smoking a cigarette they repair themselves (use an intracellular repair protein called ‘tau’) and can branch to contact neighboring neurons. However, at some point in life this neuroplasticity will be overcome and these neurons that have branched together coalesce into a ‘neurofibrillary tangle’.