After an action potential, the membrane becomes more negative than -70mV this period is called? a. Hyperpolarization b. Repolarization c. Depolarization d. Hyperdepolarization 10. After a neuron has generated an action potential, there is a brief time when a larger- than-normal stimulus would be required for the membrane to respond again. This period is called? Answer: 11. The ligand-gated channels and voltage-gated channels are formed of _______ (what biological molecule) and are found _______ (in what part of the cell)? a. Nucleic acids; in the nucleus b. Carbohydrates; in the cytoplasm c. Proteins; embedded in the plasma membrane d. Lipids; on the cell surface 12.What is the name of the disease in which the myelin sheaths of the central nervous system are destroyed? a. Poliomyelitis (Polio) b. Multiple sclerosis (MS) c. Tetanus d. Amyotrophic lateral sclerosis (ALS)