WilliamWilliam is a fourth year Distinguished Major in Neuroscience. He is currently the neuroscience department representative within the College Council, a student governing body for the College of Arts & Sciences, and on the executive board for Nu Rho Psi, the national neuroscience honor society. He has served as a TA for EDLF 5000 (Multicultural Education), and has volunteered in A Day in the Life through Madison House. He was also director of the Fozdar Symposium in 2013 where 4th year neuroscience DMP students were allowed to present their theses to a panel of judges. William currently conducts research with Professor Michael Scott, PH.D, working on a tract-tracing study of the medial prefrontal cortex (mPFC).

With a deep passion for biology and psychology, neuroscience seemed like an obvious choice. After taking an introductory neuroscience course, William developed a keen interest in investigating the underlying biological factors that influence human behavior and actions, and immediately switched from engineering to the neuroscience major. The research-oriented major has allowed him to explore cognitive-related functions driven from a molecular basis, and a diverse spectrum of research methods required to conduct experiments.

Research

Viruses themselves are a prime example of transduction. They transfer DNA from one organism to another, stably introducing a foreign gene into a host cell’s genome and utilizing the host cell’s machinery to generate proteins or more viruses. This is an example of genetic à chemical or biological signal transduction with the virus serving as the interactive medium. Humans have manipulated this process in a variety of ways, employing the viruses as a way for bacterial recombination to occur. For example, by incorporating a gene that codes for a specific protein into a bacteria and allowing it to grow, scientists can amass a copious yield of that protein to be studied in experiments. This same strategy is applied to vaccines and medicine, such as insulin, to provide medical relief for people.

Viral transduction, showing a virus introducing its DNA into the bacterial host cell's genome. The host cell then makes more viruses.

Figure 1. Viral transduction, showing a virus introducing its DNA into the bacterial host cell’s genome. The host cell then makes more viruses.

William’s current research employs the same concept of viral transduction into the prelimbic and infralimbic cortices of the medial prefrontal cortex (mPFC). By injecting a traveling virus that codes for a yellow fluorescent protein gene (YFP) into the neurons of the mPFC, the researcher can determine where the generated proteins are located since they are fluoresce under a microscope. As a result, it is possible to map the projections of the mPFC by simply following the trail of fluorescing proteins. This is an example of genetic > chemical > optical signal transduction. The interactive medium is the virus, protein, and the neurons of the brain, and the human interface is the scientist who is observing and studying the stream of light. In this way, William is trying to uncover the subtle but distinct areas of the mPFC that illustrate the diverse axonal extensions.

Neurons

Figure 2. The green cells are neurons that have been labeled with a green fluorescent protein.

In the future, William hopes to elucidate the effects of the mPFC on hedonic and homeostatic feeding. Through optogenetics, different colors of light can essentially be applied to rhodopsin proteins (proteins that react to light), integrated in the brain of living mammals, to transduce the opening or closing of sodium, potassium, and chloride channels in order to electrically activate or inhibit neuronal populations. In layman’s terms, blue light can be used to stimulate a neuron and yellow light can inhibit it. Light > electrical transduction is occurring with the rhodopsin protein as the interactive medium. The beauty of this technique is how simple and methodical the manipulations can be since every neuronal axon can essentially be controlled and studied. As a result, a variety of feeding paradigms can be employed to study how food can influence our behavior via the mPFC, and illuminate a new relationship between food and homeostatic/hedonic feeding behavior.

Optogenetic

Figure 3. Optogenetics: Blue light can stimulate a neuron, and yellow light can inhibit a neuron.

Image Credits

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