Ramón y Cajal’s meticulous studies yielded a veritable alphabet of neurons in the brain,he had to use his imagination to ... envisage the spoken language of his neurons in what he called ‘neuronal circuits.’
I know the meaning of spoken language in general but in this case it's somehow problematic. Also I recognize there must be a relationship between this "spoken language" and "alphabet" in the first line, but still I don't understand the meaning of the sentence.
So, could you please explain it to me?
The fuller text is here:
Ramón y Cajal drew highly detailed sketches of these cells with their strange cobweb patterns that looked like bits of algae strung together. Although he did not actually coin any of the key terms that are still used today, he described the elements of the nervous system in the brain more precisely than anyone before him had. He drew and explained the neurons and the axons, which are the long fibers on both sides of the neurons. He described in detail the branched projections, known as dendrites, for the first time. He adopted the word ‘synapses’ from his British friend and colleague Charles Scott Sherrington to describe the neural communication points at the ends of the dendrites. Ramón y Cajal’s meticulous studies yielded a veritable alphabet of neurons in the brain, but he had to use his imagination to generate the corresponding mental grammar, and even more to envisage the spoken language of his neurons in what he called ‘neuronal circuits.’
Who Am I? And If So, How Many? by Richard David Precht .Translated by Shelley Frisch