Figure 1. Frequency coding in the nervous system: Threshold stimulus. 1  If a threshold stimulus is applied to a neuron and maintained (top, red trace), action potentials occur at a maximum frequency that is limited by the sum of the absolute and relative refractory periods (bottom, blue trace).
Phyllis, Kentucky. Phyllis is an unincorporated community located in Pike County, Kentucky, United States. U.S. Geological Survey Geographic Names Information System: Phyllis, Kentucky.
National Women's History Museum. Phyllis Schlafly (1924-) Phyllis Stewart Schlafly was born on August 15, 1924 to John Bruce Stewart and Odile Dodge in St. Louis, Missouri. Her father was a lawyer and her mother worked to support them as a librarian and school teacher.