Once seen as the nerve cells’ foot soldier, the axon emerges as an independent decision-maker

As cells go, neurons are pretty weird.

Most other cells come in spherical blob-like shapes with a central nucleus. Neurons come in a variety of wild and spiky forms, with branching projections sprouting out of their tiny bodies in all directions.

Unlike their blobby brethren, neurons have distinct regions. There’s the cell body, home to the nucleus. Then come the axons and dendrites, the...