Elwood Henneman (1915 – 22 February 1996) was an American neurophysiologist who studied the properties of vertebrate motor neurons.
During a research fellowship at Johns Hopkins University in Baltimore, Maryland, Henneman and colleague, Vernon Mountcastle, showed that tactile information about the extremities is represented in an orderly map in the ventrolateral thalamus of the cat[1] and monkey.
[2] Further research positions followed, including at the Royal Victorian Hospital and at the Illinois Neuropsychiatric Institute (NPI) in Chicago.
At NPI, Henneman discovered that the drug Mephenesin (Myensin) inhibits interneurons in the spinal cord and thus causes muscle relaxation.
In 1957, Henneman published experimental results that showed that motor neurons that project to the same muscle are recruited on the basis of their size.