The human nervous system is composed of some 200 billion cells called neurons, about half of which are found in the brain. Neurogenesis, the process through which neurons are formed, is most active during prenatal development. Though early neuroanatomists believed that the adult nervous system is fixed and incapable of regeneration, neurogenesis actually continues throughout life. Studies have shown that lack of sleep reduces neurogenesis and exercise increases it. How is it affected by stress?
George Bernard Shaw
Back in the day
At the deadlocked 1880 Republican national convention, Garfield was nominated as a compromise candidate for president, with Chester A. Arthur chosen for vice president to appease the "Stalwart" faction of the party. However, after Garfield became president, he passed over the Stalwarts in his appointments, creating a bitter rivalry. Guiteau, who unreasonably expected to be offered a diplomatic post, shot Garfield and said, "I am a Stalwart and Arthur is president now!" When did Garfield die?
Born on a day like today
Ballard is an American oceanographer and marine geologist. While working at the Woods Hole Oceanographic Research Institution, he pioneered the use of deep-diving submersibles, took part in the first manned exploration of the Mid-Atlantic Ridge, and discovered warm water springs and the unusual animal communities that grow up around them in the Galápagos Rift. He is best known for his dramatic discovery of the wreck of the Titanic in 1985. What other notable wrecks has Ballard located?