2020 Gumbo Final - Book - Page 27
Oxytocin
Breakthrough
Story: Gunnar Viator
Photo: Karen Welsh
Design: Chloe Bryars
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Research has found neurons with oxytocin
receptors that are exclusive to female mice.
esearch led by LSU Biological Sciences Associate
Professor Ryoichi Teruyama has found neurons
with oxytocin receptors that are exclusive to
female mice.
These neurons were located in the medial
preoptic area of the brain, which Teruyama said is
known to regulate maternal behavior.
“Our hypothesis is that the cells in this part of the
brain make up a neural-circuit unique to women
that regulates maternal instinct,” Teruyama said.
Teruyama has previously led a project studying
the neuroanatomy of alligators. Seeking a fully
labeled 3-D reconstruction, his undergraduate
researchers sectioned and stained the brains
before taking detailed images. The team also
compared their samples to avian brains, as the
two are closely related.
Now, research led by LSU associate professor
Ryoichi Teruyama has found neurons with
oxytocin receptors that are exclusive to female
mice. These neurons were located in the medial
preoptic area of the brain, which Teruyama said
is known to regulate maternal behavior. “Our
hypothesis is that the cells in this part of the brain
make up a neural-circuit unique to women that
regulates maternal instinct.”
Oxytocin is a hormone found in a large variety
of animals. It is normally produced by the brain’s
hypothalamus and released by the pituitary
gland. Though often prescribed to induce
contractions for facilitating childbirth, oxytocin
acts as an excitatory neurotransmitter, and is
sometimes called the love drug for its importance
in reproduction and social behavior. “Oxytocin
is absolutely needed for you to behave socially,”
Teruyama stressed.
Teruyama’s research has located a difference
in oxytocin use between males and females but
it also revealed that the presence of oxytocin
receptors in these cells is dependent on
estrogen, a female sex hormone. Researchers
demonstrated that upon removing the mice’s
ovaries, which is the primary source of estrogen,
neurons stopped expressing receptors for
oxytocin. Receptor expression resumed upon
injecting estrogen.
This may be mirrored in pregnant human women.
During pregnancy estrogen levels are supressed
while the levels of another sex hormone,
progesterone, rise. Normal levels of both
hormones resume at birth.
Oxytocin’s suspected roles throughout the body
are numerous and varied, and because of its
antidepressant-like effects, this discovery may
shed some light on the nature of postpartum
depression, which can severely affect both
mother and child.
Although nothing has been confirmed Teruyama
said he thinks this discovery isn’t exclusive to
mice and that it could apply to all mammals.
“Many researchers have attempted to investigate
the difference between the oxytocin system in
females versus males, but no one has found
conclusive evidence until now,” Teruyama said in
a statement.
Last week the project received funding from
National Institute of Health, so research will
continue for at least two more years.
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