After NIH he did post-doctoral work in the laboratory of Walter Woodbury at the University of Washington from 1959 to 1960, and was an instructor in biophysics at the same institution (60-61).
Using recently developed small, sturdy field effect transistors, he then started to record from single neurons in the hippocampal formation in behaving rats.
Enabled by these new recording methods, Ranck' began to study the firing properties and behavioral correlates of neurons in the limbic system.
In 1984, Ranck discovered Head-Direction cells in a neighboring structure, the post-subiculum, adding a second ingredient to the navigation system of the brain.
Kubie, Bob Muller and Ranck then used quantitative, automated techniques to demonstrate the hippocampal place cells and describe their characteristics.
[6] Before that time, scientists didn't know how 'directional sense' was coded in a mammal's brain, and it was assumed to be a complex function.