One famous brain in neuroscience is that of Monsieur Leborgne. In 1861 he had a stroke that caused him to lose speech but not other skills. When he died, an autopsy revealed a distinct lesion in his brain's left hemisphere. This showed that different brain areas affected different functions: speech in one area, motor skills somewhere else. Until then, many thought the brain was an orb that did everything at once.
Monsieur Leborgne's brain is on display in the Musée Dupuytren in Paris.