The formulation of the neuron doctrine: the Island of Cajal

Santiago Ramón y Cajal (1852-1934), Spanish histologist, was the renowned formulator of the "neuron doctrine" and recipient of the 1906 Nobel Prize for Medicine or Physiology for his work on the structure of the nervous system. In contrast to the then well-accepted "reticular theory," which held that the nervous system is arranged and functions as a continuous network of cellular material, Cajal's neuron doctrine envisioned each nerve cell as an autonomous entity, establishing contact--not continuity--with other nerve cells. Cajal's theory is as well a description fitting of Cajal's own temperament, as emerges from his profound memoirs Recuerdos de Mi Vida (Recollections of My Life). The recollections detail the life of the man known from his boyhood as "capricious," the term for the goat who lives alone in the hills. For Cajal, this need for solitude and autonomy was reflected in his choice of the adventurer Robinson Crusoe as a childhood hero. Throughout his life, Cajal's desire for independence formed both his social interactions and his scientific pursuits; in his research, he preferred to remain unfettered by the academic "reticulum" of his time. A close reading of his memoirs reveals that the neuron doctrine, which envisions each nerve cell as "free," is a theory shaped by Cajal's essence, by his solitary nature and unhindered personal spirit.