Scientists can also glimpse the awful effects of Alzheimer's disease when they look at brain tissue beneath the microscope:
 Alzheimer's tissue has numerous fewer nerve cells and synapses than a well brain.
  Plaques, unusual clusters of protein particle, which are construct up between nerve cells.   Dead and dying nerve cells contain tangles, which are produce of twisted strands of a further protein.  Scientists are not absolutely sure what causes cell death and tissue deficiency in the Alzheimer's brain, but plaques and tangles are key suspects.