Faculty Profile: Dr. Pokay Ma by Mylan Vaugeois

Dr. Pokay Ma is the latest addition to the Biology Department faculty. He graduated from the University of Oregon with a Bachelor's degree in Biology, then completed graduate school at Washington University in St. Louis, specializing in neuroscience. Dr. Ma had gotten started in biology while doing research at the University of Oregon. It is his belief that with hands-on experience while still an undergraduate, students understand research and the subject better. "One way or another, everyone benefits. If you get something out of it, you benefit. And if you decide that you don't like research, that's a benefit, too," Dr Ma had said during our interview. "It's a learning experience. You can't walk in and not have learned something."

Since the Spring 1999 semester, Dr. Ma has been doing research here at Queens College. There are two main projects in his laboratory, each using a different type of fish to study neuroanatomy and its connection with behavior.

The first of the two projects focuses on the Siamese fighting fish. In this species of fish, the males are brightly colored and are very aggressive--putting two Siamese fighting fish together in one fish bowl guarantees a fight in which there will be only one victor. The brain controls this kind of aggressive behavior, especially that of the gill flare used in antagonistic displays. Beginning each fight is a certain ritual of motions and postures, which are species specific. The Siamese fighting fish will only fight with each other, but the behaviors are easy to elicit and quantify. An electromyocardiograph is used to record what the brain puts out to mediate behaviors.

This may sound difficult to quantify, but it becomes very simple with the setup that Dr. Ma has used. The fish are videotaped while the electromyocardiograph is in use. The graph data is fed into the audio channel of the VCR so that there is an obvious and direct correlation between specific behaviors and graph activity. Because these responses are so easy to elicit and quantify, the Siamese fighting fish is useful as a model to begin to understand the brain's control of behavior. Through the study of bone and muscle manipulation by the brain, Dr. Ma hopes to be able to understand the biological basis for behavior.

The second of the two projects uses zebrafish to study catecholamine systems of the brain. Catechols are dihydroxyphenols, a benzene ring with two hydroxyl (-OH) groups attached to it. Catecholamines have an amine group (-NH2) attached to the benzene ring in addition to the hydroxyl groups. They form a class of neurotransmitters in the brain, which includes noradrenaline and dopamine. The catecholamines are found in various locations in the brain including the locus coerulus, a grouping in the brain of the same kind of cell type. The locus coerulus is located in the brainstem, just below the cerebrum. In the case of zebrafish, the locus coerulus has a small number of cells--six large neurons that are easy to find and stain using immunocytochemistry.

Within this project, there are few specific goals in mind. While the cells in the zebrafish are easy to find, Dr. Ma hopes that it will be possible to identify these cells from animal to animal. Using the zebrafish as a model for brain function, it is relatively easy to make lesions in the brain and observe the behavior of the fish to determine the function of the locus coerulus. In addition to having large neurons, the zebrafish also offers the advantage of being a good system to control factors leading to the final expression of cell number. It is still unclear what regulates the number of cells in the brain, and it is hoped that through study, the mechanism of regulation can be discerned. Another benefit of using the zebrafish is the potential for studying the gene aspects of cell control. This is not a focus in Dr. Ma's lab, but it is potentially useful for study.

This is all good in theory, but carrying out the experiments prove to be a bit more difficult. Producing the lesions in zebrafish brains hasn't been too successful yet, and since the function of the locus coerulus isn't known, there is no way to tell what behaviors lesions would affect. The immunocytochemical staining of the locus coerulus in embryonic fish has been successful, as was mapping the anatomical location of the locus coerulus itself. The development has been observed, and Dr. Ma is planning to take electrophysical recordings of cells in order to understand their physiological function.