When combined with results of other neurological tests, and in the context of a thorough medical history, atrophy of the brain (shown here in an MRI scan) sometimes indicates Alzheimer's.
Simon Fraser/Science Source
Jonathan Keleher talks with a colleague, Rafael Wainhaus, at work. Keleher was born without a cerebellum, but his brain has developed work-arounds for solving problems of balance and abstract thought.
Ellen Webber for NPR
Prion protein can be infectious, spreading from cell to cell in the brain. Here four nerve cells in a mouse illustrate how infectious prion protein moves within cells along neurites — wire-like connections the nerve cells use for communicating with adjacent cells.
Barotrauma can cause a fish's eyes to pop out of its head and its stomach to be pushed out of its mouth, according to Chris Lowe, a marine scientist at California State, Long Beach.