The Discovery of Head Direction Cells: A Personal Account

This article is my recollection of events surrounding the discovery of head direction (HD) cells by Jim Ranck in 1984 and the first journal publications 6 years later. Ranck first described the fundamental properties of HD cells qualitatively in a Society for Neuroscience abstract (1984) and in the proceedings to a conference. Ranck, however, was convinced by Bob Muller, a faculty colleague in the lab, to delay writing up Jim's discovery until they developed a two-spot video tracking system, which would enable proper quantitative analyses. The development of this system was complex and was still undergoing development when I arrived in the Brooklyn lab in 1986. By this time, Jim had begun to refocus his efforts on thinking about the relationship between space and manifolds and was no longer engaged in active research. It thus befell me (unintentionally) to complete the recordings of these fascinating cells. This endeavor involved recording additional HD cells with the new video tracking system, monitoring the cells' responses following a series of environmental manipulations, and performing quantitative analyses on the data. Throughout 1987, I recorded most of the cells that would form the basis for our 1990 papers published in the Journal of Neuroscience. Along the way, there were many events and emotions: luck, excitement, humor, frustration, tutorials, unintended outcomes, and long-lasting friendships. I was guided and supported during this time by both Bob Muller and John Kubie, but remain forever grateful to Jim for this wonderful opportunity.