Philip Brooks, Addiction Neuroscience at UCSD, Week 2

Monday & Tuesday: We conducted a full experiment run-through starting with vapor administrations. Mice were placed in airtight containers connected to a pipe system that vaporized nicotine liquid and dispensed a premeasured amount into the chambers at set intervals. Post-vapor administration, the mice were moved to a separate room and placed in an “open field,” a square space with walls, where their behavior was recorded for 10 minutes to assess stress levels. After a rest period, we began perfusions on the mice, which involved replacing their blood with paraformaldehyde to preserve the cells for future analysis. The collected blood was spun in a centrifuge to separate the serum, which I was responsible for extracting. Performing serum extractions independently was a gratifying experience, as I was trusted to handle this part of the procedure without supervision. We processed five mice each day, totaling ten. The importance of our work is underscored by the drug addiction crisis I witness in the homeless communities near my commute route, highlighting the potential impact of our research.

Wednesday: We utilized two brains harvested from Monday and Tuesday for slicing with a cryostat. This machine can slice tissue into sections as thin as 10 micrometers. After freezing the brain, we cut a flat base on the cerebellum and mounted it using Tissue-Tek OCT, a freezable compound that acts as glue. Each mouse brain, despite being smaller than a pinky toe, yielded over 100 slices. We extracted these slices in batches of six with a fine brush and placed them in a vial containing PBS and sodium azide to preserve them. The process was meticulous, as the slices were fragile and difficult to transfer if the brush was wet. When the lab technician left halfway through the day, I took over slicing the second brain on my own while my mentor focused on her PhD thesis.

Thursday & Friday: These days were primarily spent mounting the brain slices from Wednesday onto glass slides for future microscopic analysis. This process required precision, as the slices, now fully saturated in PBS and no longer frozen, were extremely fragile. We poured the slices from the vial into an open container of PBS and transferred them one by one with a fine paintbrush onto slides. It took several tries to perfect this technique, as any mistake could tear or scrunch the slices, making them unusable for microscope viewing. Excess PBS was carefully dried off the slides to allow the slices to set in place, a step that also required great care to avoid damaging the slices. I spent most of Thursday and all of Friday mounting slides alone, enjoying the opportunity to listen to music and develop a rhythm in my work.

Personal Life: Outside of work, I continued surfing whenever possible and began spending more time with my host parents, who returned last Sunday night. I tried various new foods with them and enjoyed activities like bodysurfing and disc golfing with my host dad. I’m thoroughly enjoying my work and the beach summer lifestyle and am excited for what the next week holds.