Download L A Journey into the nervous system CtY neuroscience

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CtY neuroscience
A Journey into the
nervous system
L
by Carli Huber
ast January, for the fifth consecutive winter, I pored over a CTY course catalog to find my next summer
class. I knew I wanted to continue my pursuit of biology and chemistry, but I had discovered some things
about myself over the years. For example, I realized that I don’t enjoy studying large-scale biology, such as
entire ecosystems. Instead, I’m drawn to the microscopic world of biology, where the chemistry involved
is especially complex. And in addition to the natural sciences, I had developed an interest in psychology. As I looked
through the catalog, I was excited to see a course that combined all my interests: Neuroscience.
Molecular Foundations
In June, I arrived at Dickinson College in Carlisle, Pennsylvania, ready
for my latest CTY session. As usual, the dorms, activities, and meals were
fantastic, but neuroscience was my focus, and I was instantly obsessed.
Neuroscience can be studied at the molecular level, at the cellular
level, in the structure of the brain as a whole, and from a psychological
perspective. I soon discovered that understanding neuroscience at any
level required explicit knowledge of the molecular chemistry involved.
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I learned that nerve cells, or neurons, communicate with one another
by a complex process that involves both electrical and chemical signals.
Neurons are known as “excitable” cells because when they are stimulated
(chemically, electrically, or mechanically), they generate an electrical impulse that spreads throughout the entire cell. When the impulse
reaches the end of the cell, it causes the cell to release a chemical called
a neurotransmitter, which can chemically excite nearby neurons. The
neurotransmitter released by one neuron can trigger an impulse in the
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next. Then, like falling dominoes, a series of impulses travels
from one neuron to the next, sending a signal from one part of
the nervous system to another. I was fascinated by the combination of physics, chemistry, and biology that makes possible our
thoughts, sensations, and actions.
branching out
Each day, we would dissect sheep brains, learning the functions
of nerves and various parts of the brain. I enjoyed slicing the
brains at different angles, which gave me several perspectives
of a single structure. The hands-on experience also allowed me
to observe things I had at first only read about. My personal
favorites were the corpora quadrigemina: four mini lobes—one
pair for ocular stimuli, one for auditory—in the midbrain that
allow a person to react quickly in hazardous situations without
conscious thought.
We studied the functions of the many lobes, stems, and
nerves in part by learning how the body functions without
them. I was intrigued by the case of Phineas Gage, a man who
was injured in an explosion that drove a large iron pole through
his head, damaging the forward portion of his frontal lobe.
Gage survived the accident, although changes to his personality
caused his friends to describe him as “no longer Gage.” He was
impulsive, uninhibited, and prone to speaking “in the grossest
profanity.” His was the first case to show a connection between
the frontal cortex and personality.
Next we examined the sense organs, including the eyes, nose,
tongue, and ears, and then moved on to study diseases and conditions of the nervous system. Problems in the nervous system
are extremely variable, and can affect nerves, the brain, or both;
many are without cures.
For one project, each student spent a few days studying a
single disease in depth and then presented their topic to the
class. I chose Huntington’s disease, a devastating genetic disorder
in which nerve cells in the brain waste away. The age of onset
depends on how many times the gene has been passed down
in a family; the more times the gene is passed down, the earlier
the age at which symptoms appear. As cells in the brain begin
to deteriorate, people with Huntington’s disease experience
hallucinations and problems with memory, speech, movement,
and coordination. As is the case with many other diseases of the
nervous system, there is currently no cure, only medications to
manage symptoms. Through this project, we all came to understand the urgency that fuels neuroscience research.
Mind & brain
After studying the physical aspects of neuroscience, we delved
into some of the mental aspects: consciousness, instincts,
emotions, intelligence, depression and euphoria caused by
endorphins, and the effects of drugs. Endorphins were a main
connection between the physical and mental approaches, and
we examined how deficiencies or excesses of this or other
neurotransmitters result in conditions such as depression,
schizophrenia, and anxiety.
Along with learning the basics of neuroscience in class and
labs, we read dozens of articles on a range of psychological and
physical subjects related to the nervous system. Some of my
favorites included an examination of synesthesia, a condition
where a person’s senses blend together (for example, a person
might perceive letters or numbers as having colors); a report on
the impact of Wernicke’s or Broca’s aphasia (problems with comprehension of words and problems connecting ideas to words,
respectively) on deaf people who use sign language to communicate; and a comparison of male and female brains, which differ
quite a bit in size, amount of white and gray matter, and volume
of certain lobes, to name just a few differences.
I will admit that taking this course injured my ego a bit: the
material was challenging enough that this straight-A honor student failed two quizzes. But I loved what I was learning; I have
continued to explore neuroscience topics since the course ended,
and I am even considering neuroscience as a college major. The
molecular chemistry and biology definitely improved my understanding of the human body, but I think the most valuable thing
I learned was how much I have yet to learn.
Carli Huber is a junior at Avon Grove
high school in Pennsylvania, where she is
a member of the cross country team, the
national honor society, and the
academic competition team. in her free
time, carli enjoys skiing, snowboarding,
reading, and painting. she plans to major
in chemistry, neuroscience, or chemical
engineering in college.
Learn more about CTY Neuroscience and other summer courses at cty.jhu.edu/summer.
www.cty.jhu.edu/imagine
imagine
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