The neuron doctrine, the mind, and the arctic.

The late 19th century and early 20th century represent an era of significant progress and important discoveries. Explorers of unknown continents interacted with pioneers of neuroscience, including the founders of the neuron doctrine, which asserted that nerve tissue was composed of individual cells that were genetic, anatomic, functional, and trophic units. Fridtiof Nansen (1861-1930), an arctic explorer and a cofounder of the neuron doctrine, knew Sigmund Freud (1856-1939), a neuroscientist and the founder of psychoanalysis, as well as Harvey Cushing (1869-1939), the father of modern neurosurgery. This is an account of the evolution of the neuron doctrine at a time of great explorers and scientists, with insight into their common interests and interactions on scientific and social levels.