Researchers used advanced microscopy techniques to examine brain tissue from rats with Alzheimer’s disease and compared it to healthy rats. They found that Alzheimer’s disease causes damage to connections between brain cells (synapses) in a brain region important for thinking and memory. Specifically, the connections were weaker and smaller, and many new spine-like structures formed but didn’t properly connect to other cells, suggesting the brain may be trying unsuccessfully to compensate for the disease.