The first week, we were just looking at surface structures so we were only able to cut the dura mater off of our sheep brain. (The "dura mater", meaning "tough mother", is aptly named. That membrane was hard to cut through!) This week was more interesting, as we actually got to see internal structures of the brain. First, we used a scalpel to slice down the center of the brain just far enough so that we could see the corpus callosum (a large tract of fibers which connects the two hemispheres of the brain and allows them to communicate). Then, the preceptors brought out the knife. This was huge. They showed us how to cut the brain properly, without sawing at it, so that we would not excessively damage the structures that we wanted to see. Actually identifying things, both external and internal, is somewhat harder on these sheep brains than on the human brains that I have seen. But it is amazing the degree of similarity between brains of different species.
Along these lines, I was looking at comparitive drawings of several species' brains in our text tonight which showed relative size and convlolution. Generally, it is assumed that the more bumps and groves a brain has, the more intelligent, etc, a species is. This is because traits such as intelligence, rational thinking, and personallity are contributed to the cerebral cortex, the part that forms the bumps and groves on the surface of the brain. Anyway, while looking at the drawings, I was stunned by the appearence of the dolphin brain. It is actually more convoluted than the human brain. I was also surprised that the rabbit brain seemed almost completely smooth. I have a bunny at home, and he is sometimes quite clever and has quite a personality (he is so cute!).