Bregma marks the spot. Well, sort of.

I apologize that this post is so long in coming. I typed this post up last week, but unfortunately I accidentally erased it all. Smooth, I know. I did not have time to retype it this weekend, as my parents were visiting me in LA. We had a lot of fun! We did many of the tourist activities in LA which was cool since I hadn’t done many of those things yet even though I have been living in LA for two months! I will post those pictures soon.



Several weeks ago, I was able to assist in my first surgery ever! It was awesome. Before I begin my description on tumor implantation, I want to reiterate that all procedures are done to ensure that the animals are treated in the most humane way possible. The mice are first anesthetized. Then their heads are shaved. Once they are completely under anesthesia, they are placed on the stereotactic frame, as shown above. After the mice are secure, betadine is applied to the incision area and the skin covering the skull is cut. The skull is exposed and the bregma is located. The bregma is actually easier to locate when the skull dries slightly. The bregma is the point of intersection between the coronal suture (horizontal line in the picture to the left) and the sagittal suture (vertical line) where the frontal and parietal bones meet. We use the bregma as the “zero point” or the point of reference. Once we find the bregma, we utilize the stereotactic frame to find the correct point in the right hemisphere where we will inject the tumor cells. A burr hole is created in the skull using a hand drill, a needle is inserted into the hole, and 50 K tumor cells are injected into the hole. After injection, bone wax is applied to cover the burr hole, the skin is clipped together, and pain killers are injected subcutaneously. The mice are observed closely for several hours after surgery and then each day until terminal symptoms become apparent. This particular type of surgery can be performed to derive tumor lines or to observe the effects that different treatment types have on tumor growth and mouse survival time.