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.
The junction between the axon terminals of a neuron and the receiving cell is called a synapse. (Synapses at muscle fibers are also called neuromuscular junctions or myoneural junctions 1  .). Action potentials travel down the axon of the neuron to its end(s), the axon terminal(s).he neurotransmitter at excitatory synapses depolarizes the postsynaptic membrane (of a neuron in this diagram). 1  Binding of acetylcholine to its receptors on the postsynaptic cell opens up ligand-gated sodium channels. 2  These allow an influx of Na + ions, reducing the membrane potential.