At rest, the neuron has an electrical resting potential (in a state of polaraization: 2. When stimulated, a flow of ions in and out through the cell membrane reverses the electrical charge of the resting potential, producing an action potential, or nerve impulse: 3. The original distribution of ions is restored and the neuron is again at rest. The myelin sheath: tube-like, fatty, whitish, insulation layer derived from glial cells, most commonly found in the nervous systems of higher animals, ex. Multiple sclerosis when the persons own immune system attacks the myelin sheath and damage to the myelin sheath disrupts the delicate timing of nerve impulses, resulting in jerky, uncoordinated movements. Neurotransmitters: neurons produce neurotransmitters chemical substances that carry messages across the synapse to either excite other neurons or inhibit their firing. Benzodiazepines (drug commonly used to treat anxiety disorders) enhances gaba activity.