job working for Uncle Sam in the public health system. Fortunately for
Mahlon DeLong, MD (and humanity), the National Institute of Health (and
its NIMH), qualified as an acceptable stopover.
Mahlon DeLong (b. 1938) attended Stanford University, spending time
with a physiologist who studied the nervous system of the crayfish. That
professor was Donald Kennedy, the future president of Stanford and editor
in chief of Science.^19 Not exactly the typical preparatory material for
medical school, but DeLong’s interest in biological systems was piqued,
and he headed east to Harvard Medical School, graduating in 1966. He
stayed in Boston to begin his medical residency, but the logistical demands
of the Vietnam War gave rise to the infamous 1969 Vietnam draft lottery.
Rather than risk being deployed in the medical corps overseas (as young
physicians were), DeLong accepted a position as a research associate in
the NIMH laboratory of Edward Evarts. For the next five years, DeLong
was part of the team that spearheaded the inquiry into the circuit board of
the mind.
When DeLong arrived, he soon realized that most of the easily
approached areas of the brain had been claimed by other research
associates of Evarts’s. The out-of-the-way center of the brain was poorly
understood, and for DeLong it “was like exploring and charting unmapped
Africa or the Amazon.”^20 Since all the “good stuff” (such as the motor
cortex and cerebellum) was relatively well understood, Mahlon DeLong
turned his attention to the basal ganglia, where the normal anatomy and
physiology were almost completely unknown. The young researcher, with
no PhD in the field, quickly discovered an astounding fact: just as there
was specificity in the function of cortex, there was localization for the
nerve pathways that encode movement in the basal ganglia.
As Paul Broca had predicted, brain functionality was local; there are
extremely specific areas of function in the brain, such as the motor cortex.
Not only is all muscle function controlled in the “motor strip,” there is a
bizarrely composed plan of motor responsibility in this ribbon of wrinkly
brain, and can be represented to the reader with the “homunculus,” or
“little man.”
As one can see in the diagram, the localization for sensation is
preposterously predictable. For instance, sensation for the knee lies near
the top of the head, where the hemisphere of the brain takes a right angle
and the split between brain halves occurs. Similarly, the movement of the