We’ll look at the brain on four different levels:NEURAL STRUCTURES. Physical parts of the gray matter like the amyg-
dala and the hippocampus—which mean “almond” and “seahorse,”respec-
tively—were named according to what anatomists thought they looked
like, much the same way early astronomers divided the stars into constel-
lations. The stars seem to fit together to make human figures and animals,
but seen through a telescope, they reveal themselves as unlikely combi-
nations of near suns and distant galaxies. So too do almonds and seahorses
fall apart into separate cells when observed through a microscope or by
their electrical activity. Functions in the brain are never localized into one
particular structure, and structures are always involved in many different,
and seemingly unrelated, functions. Still, it’s often useful to think about
fear and anger being, at least somewhat, localized in the amygdala and a
little piece of the tail of the hippocampus.
CHEMICAL CONNECTIONS. Though their activity is electrical, brain cells
are not physically fastened together like circuits in a computer. The wires in
the brain are made of chemicals called transmitter substances. That’s where
serotonin and norepinephrine come in. As we’ll see, starting in the next chap-
ter, virtually all psychoactive medications work by affecting the operation of
transmitter substances.
The same transmitter, say serotonin, is often the link between many
very different structures and functions. This is why a selective serotonin
reuptake inhibitorlike Paxil might legitimately be prescribed for any explo-
sive disorder described in this book.
THEORETICAL SYSTEMS. Sometimes it’s useful to group brain structures
according to what they’re supposed to do. No one can say exactly where
the limbic system is, or what it’s made of, but we can think about circuits
of cells working together to regulate emotion. Likewise, you’ll never see
the sympathetic or parasympathetic systems on a map of the brain, but
they are still useful in describing how the mind and body work together.
PROGRAMS. As if knowing the names of the hardware weren’t difficult
enough, there’s still the software to consider. The brain comes equipped
Basic Calming Technique ❧ 53