Some seniors are completing their Bowdoin educations by creating original honors projects that help us see the world in new and interesting ways. This is the first installment of the year in a continuing series that highlights these projects.
Ever want to have your cake and eat it too? Erica Ehrhardt '10 can.
"We're studying lobster hearts," said Ehrhardt when commenting on her senior honors project.
Ehrhardt, a German and biochemistry double major, is working with Professor of Neuroscience Patsy Dickinson to study the heartbeat of a lobster. The obvious question that claws at many of us is "Why?"
According to Ehrhardt, the rhythmic pattern of the heart is controlled by the cardiac ganglion, which is made up of only nine neurons. Of these nine neurons, four are pacemakers that send out a pattern to stimulate the neurons of the heart. Ehrhardt's specific research concerns measuring the bursting of the cardiac ganglion.
The heart of the American lobster represents a relatively simple nerve-muscle system.
"We want to know why the [neurotransmitters] have more of an effect when [the cardiac ganglion] is isolated," said Ehrhardt.
While other studies have examined the embryonic growth of the heart of lobsters, Ehrhardt's honors project is unique in its scope.
The primary method used by Ehrhardt in her study is measuring the nitric oxide levels produced by the heart. When the heart contracts, it produces more nitric oxide. The nitric oxide then diffuses up to the cardiac ganglion and alters its pattern.
For those of us who have only viewed a lobster's heart while pushing aside the insides of the lobsters, Ehrhardt's research studies the effects of the neurotransmitters that control the heart.
"We can remove the heart, and it beats on its own under proper conditions for up to eight hours outside of the lobster," said Ehrhardt.
After removing the heart from the body, Ehrhardt inserts a neurotransmitter, also known as a peptide, to control the heartbeat.
Ehrhardt's interest was sparked in this intricate area of research after studying the central nervous system of grasshoppers during her semester abroad in Germany. Upon her return, Ehrhardt started her research at Bowdoin in August 2009.
Other students have studied the same area with Dickinson in past years. However, previous student researchers worked to find the difference between an isolated and non-isolated cardiac ganglion. Ehrhardt decided to take this hypothesis one step further to see if she can regulate the lobster's heartbeat.
Recently, Ehrhardt, who has been working alongside Matt Bowers '10, has been introduced to a new method of controlling nitric oxide levels using a smaller part of the muscle and morphine.
"[The morphine] acts directly on the muscles and changes the oxide production, so there is no need for the cardiac ganglion," said Ehrhardt. "We've been trying to replicate this."
So how does Ehrhardt have her cake and eat it too?
"We save the tails and claws and eat them with the other people in the lab," said Ehrhardt.
Ehrhardt plans to pursue graduate school after she graduates this spring.