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.
Pine Knot, KY. Sponsored Topics. Pine Knot is a census-designated place (CDP) in McCreary County, Kentucky, United States. The population was 1,680 at the 2000 census. Pine Knot is located at 36Â°39â²41â³N 84Â°26â²25â³W / 36.66139Â°N 84.44028Â°W / 36.66139; -84.44028 (36.661333, -84.440412).