My internship site is Columbia University Medical Campus in New York City. I work as a summer student in both Sulzer and Harrison Laboratories. Dr. Sulzer and Dr. Harrison are both Ph.Ds in their respective fields. Dr. Harrison is in charge of a research project, within the anesthesiology department, as its principal investigator, while Dr. Sulzer is the principal investigator of a project within psychiatry department. For the summer, I am registered as a psychiatry student at Columbia, although multiple fields/departments can technically apply to my position. The principal investigators and their respective lab teams are all currently working together on a conjoined project, wherein each member of either lab leads a specific project within a more broad area of research. The umbrella topic which incorporates all of these research projects entails the multitude of effects and responsibilities that dopamine has within the brain. This overarching subject matter serves as a foundation for a great variety of possible diseases/disorders to tackle. To illustrate the magnitude of this subject matter, medical problems from which we stand solutions by studying dopamine projections throughout the brain include: Parkinson’s (among other motor function disabilities), addiction, and schizophrenia. On a more day to day level, dopaminergic neurons and their projection targets influence just about every decision a person makes in a day. The specific project which I am a part of focuses on the mechanisms of addiction, especially in regard to alcohol, by utilizing animal models. It is fairly well accepted throughout the scientific community that drugs of abuse exert their powerful grip on the brain by “hijacking” the rewards circuitry (a process of reward/consequence that provided humans a vast evolutionary advantage throughout the span of our species existence). This project is headed by an alumni of Tulane University who is currently a Ph.D student at Columbia. The goal of her project is to demonstrate the existence and heterogeneity of dopamine neuron sub populations in the ventral tegmental area (VTA) based on their projection targets throughout the brain. My role will incorporate two main tasks. First, I will assist in the labeling of neurons, within mice which have been exposed to ethanol(alcohol), via immunohistochemistry. Particularly we will be using retrobead labeling to analyze the various targets of VTA neurons, which will fluorescently highlight the dopamine neurons in the VTA and the specific brain structure that each neuronal population fires to. I will be responsible for applying the antibodies and staining which actually make these neurons and retrobeads visible under the microscope. The neurons will appear as four possible colors, where in: blue(DAPI stain) will highlight all neurons in the brain section, green(retrobeads) will show the neurons in the target brain structure, red (Nissl stain) will show the dopaminergic neurons within that VTA that project to targets brain structure neurons, and yellow will show other types of neurons (e.g. GABA, glutamate, etc…). The brain regions of interest targeted by the VTA include: the medial Prefrontal Cortex, nucleus Accumbens(nAC) lateral shell, nAC medial shell, nAC core, and the basolateral amygdala. A two day process, I have already prepared my first few slides with the slices of a single mouse brain. This leads me to my next duty which will be to quantify the subpopulations of dopamine neurons in the VTA based on their projection target. I will be using a confocal microscope which allows a clear, highly magnified view of these neurons and their targets. I am in the process of being trained on this microscope which is a highly delicate and complex machine. As part of my training, I have looked at the previously mentioned slides which I had prepared, and I was able to visually see exactly what I had been working on earlier that week. I have also attended two lab meetings, which are held on Friday mornings. During which the members of the lab discuss the work that they have done since the last meeting, so that each person involved in the lab contributes information from their specific project, providing the whole team with a more full perspective on the overall project.