Whether you are an apple tree or an antelope, survival
depends on using your energy efficiently. In a difficult or dangerous
situation, the key question is whether exerting effort — sending out roots in
search of nutrients in a drought or running at top speed from a predator — will
be worth the energy.
In a paper published online Nov. 18 in Nature, Karl
Deisseroth, MD, PhD, a professor of bioengineering and of psychiatry and
behavioral sciences at Stanford University, and postdoctoral scholar Melissa
Warden, PhD, describe how they have isolated the neurons that carry these
split-second decisions to act from the higher brain to the brain stem. In doing
so, they have provided insight into the causes of severe brain disorders such
as depression.