STED: Small Scale, Big Breakthroughs

Learn about the tools and techniques used by Max Planck scientists to study the brain. 

November 29, 2017

By Corey Moran

Watching Dr. Christian Wurm boot up the Imspector software for the very first time filled me with a mixture of fascination and trepidation. At first glance, Abberior’s software interface for the STED microscope is reminiscent of a pilot’s cockpit; blinking lights, snippets of recognizable phrases, and a multitude of virtual buttons all laid out in a seemingly organized, but completely unfamiliar fashion. I continued to watch as he masterfully navigated through the myriad of submenus, adjusting this and that to his liking and preparing the microscope for the day’s imaging. It struck me in that moment that Dr. Wurm, the CEO of Aberrior Instruments America, would only be here to train us for one week. In that short time, I needed to become a proficient helmsman of this foreign vessel. Daunting? By all means, yes, but I was excited to take on the challenge and add another piece of microscopy to my arsenal.

You might be wondering now who the “me” is in this story. Hello to everyone reading, my name is Corey Moran and I am a graduate of the University of Florida with a degree in microbiology and cell science, with an emphasis in neuroscience. I had the good fortune to intern in Dr. Ryohei Yasuda’s lab two summers during my undergraduate work and two years now full time. MPFI served as my first foray into neurobiological research and what an incredible experience it has been.

Working in Dr. Yasuda’s lab at MPFI, I have become versed in microscopy techniques ranging from 2-photon to FLIM-FRET to confocal. These imaging techniques, which I can only describe as simply elegant, provide a novel avenue to the inner working and function of the complex tapestry of cells that comprise the human brain. In Dr. Yasuda’s lab, the main focus of research involves the study of the intricate symphony of signaling proteins that interact during the process of learning and memory. To study these neurological events, we look directly at a protein’s behavior during the physiological process called synaptic plasticity, which is the ability of a synapse (communicational connections between neurons) to change over time.

Specifically using the STED, I have been working with my colleague, Dr. Jie Wang, who has been studying a particular endosomal protein. Research has established the critical importance of this protein as it relates to the packaging and shipping of cellular material within brain cells. An important new discovery made by Dr. Wang takes us one view deeper into the multifunctional roles that proteins play. Her research shows that the protein in question attenuates the process of synaptic plasticity, acting as a molecular brake. This action slows the process of learning and memory for reasons that are not yet fully clear. Once we learned of the protein’s particularly unique role, the next logical step was to investigate the region of the cell where its biological effect is exhibited.

The endosome is a dense and complex intracellular network that is responsible for packaging and shipping cellular cargo like proteins, lipids, and other macromolecules all throughout the cell. This network is difficult to study due to the fact that it consists of varying types of unique mini-compartments. Our protein in question could associate with any number of these smaller compartments or even reside in multiple locations. The size of these endosomal compartments can be well under the 200nm resolution limit of traditional light microscopy. So to parse this information out, we needed the superior resolution that only the STED could provide us.

Currently, we are embarking on a set of co-localization studies. These types of studies involve looking at hundreds of neurons to see if our protein of interest resides in the same locations of other previously identified proteins within the cell. Uncovering this piece of the puzzle will provide a greater understanding of the protein’s location within this network. Knowing the location, we can then extrapolate what type of function our protein may have based on the identified functions of the compartment itself and what other proteins also localize to it. This information will ultimately give us a more complete picture of how this protein contributes to the overall process of learning and memory.

Concurrently, I am utilizing the STED to validate research tools to study a secondary protein that looks to be critically involved in the pathological cascade of Alzheimer’s disease. My work in conjunction with my mentor Dr. Erzsebet Szatmari is still in the very preliminary stages. Hopefully, this work will lead to disease-relevant discoveries as our experiments progress.

The intersection of super-resolution microscopy and neuroscience is a relatively new phenomenon and a frontier where only the surface has been scratched. The capability of super-resolution microscopy will continue to develop and expand exponentially in the very near future. One of the most exciting goals is to dynamically fuse these two highly specialized fields in order to study complex neuronal functions, such as synaptic plasticity, in real-time with nanoscale, crystal clear resolution. Currently, at MPFI, we are working on just that, pushing our optics further into the future to make an immediate impact.