A columnist is someone who writes for publication in a series, creating an article that usually offers commentary and opinions. Columns appear in newspapers, magazines and other publications, including blogs. They take the form of a short essay by a specific writer who offers a personal point of view.
This positive spike constitutes the action potential: the electrical signal that typically moves from the cell body dlown the axon to the axon terminals. The electrical signal moves down the axon like a wave; at each 84 Ch apter 3 Biopsycholo gy point, some of the sodium ions that enter the cell diffuse to the neJ1.'t section of the axon, raising the charge past the threshold of excitation and triggering a new influx of sodium ions.
That white stuff is myelin, a fatty tissue that covers much of the long axons that extend out of our neurons. Scientists have found that myelination increases the speed and strength of the nerve impulses by forcing the electrical charge to jump across the myelin sheath to the next open spot on the axon. In other words, myelin turns the electrical signal into the brain version of Nightcrawler, the teleporting X-Man.