First Day

The first day was interesting and informative. I am working at a WashU lab in the Medical Campus. It is on Euclid Ave near Barnes Jewish hospital South building and Eric P. Neumann Education center. The lab PI is Dr. Corbo who specializes in neuronal research. His assistant is Connie. They both were very welcoming and showed me the ropes today. I even got a Washington University badge....woohoo! The lab also has a couple of MD, Ph.D. students. The campus is huge and I am getting my daily exercise walking from the parking lot to the lab.

I spent the day learning about what they have been doing in the lab since January. Today's entry will be about the lab in general and what I read today. In the beginning, it took me 30 minutes to get through 5 sentences and I was just reading the Abstract! As I spent more time reading the articles, I was able to better understand the project. Dr. Corbo has given me a lot of good articles to read. This should help me understand the basic science behind my project in his lab.

Humans don't want to conduct experiments on other human beings without testing first on cell culture and animal models.  However, brain development studies are hitting a wall currently with using mice and other animals as models for the nervous system. Human brains are not fully represented by animal brains. Recently three separate groups of scientists have found a way to use pluripotent stem cells to create a cerebral organoid.

Pluripotent cells have been a huge breakthrough for many scientists interested in various fields. A term that you may be more familiar to is stem cells. While stem cells are actually taken from a fetus, pluripotent stem cells (the official name) are, most of the time, altered skin cells that have reverted back to a stem cell-like state. Scientists have then been able to change the pluripotent stem cell (abbreviated in scientific literature as PSC) into any cell in the body with the right chemical concoction added to the medium in which the PSC reside. The concoction is determined by trial and error.

There are a couple of problems the three groups had to address. First, this process has never been done before with the goal to create neuronal cells. Each group had a slightly different way of attacking the issue. Second, when the process worked, the cells obtained were not good enough to actually do any scientific work on. This was fixed by using a scaffolding material. The most successful choice was Matrigel. Matrigel is a hydrogel that contains extracellular proteins. The proteins act as an anchor to allow cells to grow and spread out more. Third, the normal method of creating these cells only created a flat sheet of tissue. While that is a little interesting, it's not very useful for the scientists who want to study a three-dimensional organ. So, they "agitate" the solution. That basically means that they gently and continuously swirl the solution of cells around. This creates a 3-D shape resembling a sphere (really just looks more like a blob). What's even more cool is the fact that cells on the inside are starting to die and leave cavities. That sentence sounds weird because scientists want live cells. Brain actually has cavities called ventricles that are extremely important to the structure and function of the brain. So, noticing that the core cells are dying is a really good sign that the process is working to create a clump of tissue that is acting like a brain that is developing. Another cool thing is that if the cells are stained with using antibody stains (use one antibody to tag a specific protein found on a specific cell and use another antibody with a fluorescent protein attached to tag the first antibody) scientists can see that the cells have also started to differentiate and even form layers that approximately look like the forebrain, midbrain, and hindbrain along with the meninges and many other structures.

The lab could not get either of the three procedures to work as well as they were hoping. They combined the three ways of producing the cerebral organoids and created a new protocol. From what I understand, my job is to slice these organoids like a loaf of bread with the width of each slide ranging from 4 to 10 microns. I then use antibody staining to see if the cells have aged, developed, and/or differentiated at all.

If I get positive results, the lab will start doing their actual experiment. I will write more about the experiment on another day.