DURHAM, N.C. -- Imagine how much easier learning the intricate structures of the brain would be if only you could carry one around with you to study -- a truly remarkable brain that you could slice, Aunslice@ and even reslice in another plane to explore its complex anatomy. And what if you could even pick from a list of brain structures -- ranging from the abducens nerve to white matter -- and instruct your portable brain to highlight the structure in vivid color amidst its otherwise undifferentiated beige tissue?
Duke medical students enjoyed just such a capability for the first time this year, thanks to a new neuroanatomy teaching program called Sylvius: Fundamentals of Human Neural Structure.
Developed by neurobiologist S. Mark Williams with support from the department of neurobiology and the medical school, Sylvius was provided on CD-ROM to medical students taking introductory neuroscience. The program was designed as an electronic adjunct to the textbook Neuroscience (Sinauer Associates, Sunderland, Mass., 1997), edited by neurobiology department chairman Dale Purves and faculty members George Augustine, David Fitzpatrick, Lawrence Katz, Anthony-Samuel LaMantia and James McNamara.
Duke medical students have given the new program high praise on feedback forms, using such terms as "very cool," "fantastic," "extremely helpful," and "absolutely wonderful program." One student commented that Sylvius was "Very helpful in obtaining a visual representation of the three-dimensional structure of brain structures. Don't know how I'd do it without the Sylvius program."
Williams named Sylvius for two renowned Renaissance anatomists who believed in learning body structures by careful dissection. And dissection is precisely what Williams had to do in order to produce the images for the Sylvius program. "Using a human brain specimen from our teaching lab collection, I sectioned it in one plane and had digital photographs made of each section. Then for the other two planes, I glued the sections back together and resectioned them each time, taking digital images.
The result, said Williams, was that Sylvius was based on images of the same brain sectioned in three planes, which greatly simplifies the task of students attempting to understand brain structure.
"While the gross structure might be the same from brain to brain, it was very helpful for the students to see the same brain in different planes," Williams said. "Also, the program can combine, say, a horizontal section and coronal section to show a corner, giving the student a greater appreciation for the three-dimensional organization of structures located deep within the brain." Once the images were obtained, however, Williams was still faced with a considerable challenge in computer graphics to render them useful.
"By the third sectioning, the brain was basically in cubes, so there were plenty of cut marks and other defects that I had to airbrush out to arrive at acceptable images."
Sylvius, includes more than 1,500 such images, organized into four modules: surface anatomy, sectional anatomy, a brainstem module and an index listing of some 200 structures. In the index, mouse-clicking on a structure name calls up an image with that structure highlighted in color. The program also includes a "magnifying glass" that users can slide over the images to see them in greater detail.
According to Williams, Sylvius is quite different from the several other neuroanatomy programs on the market.
"We show the brain in higher resolution, and our program gives the user a sense of dissecting the same brain in the three major anatomical planes," he said. "Also, we custom-tailored Sylvius specifically to the needs of the medical students, and it integrates very readily into the neuroanatomy teaching laboratory."
Not content to rest on his laurels, Williams has already begun work on an improved version of Sylvius, which he expects to be ready for the spring semester.
Sylvius 2.0 will include three-D models of individual brain structures that students can extract from the whole brain for examination. For this capability, Williams is using data from National Library of Medicine's Visible Human Project, in which human bodies were photographed thin section by thin section, and collaborating with Bradley Smith of the Duke Center for In vivo Microscopy.
Williams is also producing a new set of brain sections that will be displayed both as photographs and magnetic resonance images. It will give students side-by-side comparisons of the same structures visualized with different methods, thanks to a collaboration with the department of radiology's Gregory McCarthy, director of the Duke Brain Imaging and Analysis Center, and James McFall, co-director of the Duke Center for Advanced Magnetic Resonance Imaging. Developed using the multimedia software Director, by Macromedia, Sylvius can run on either a PC or a PowerMac. Sylvius is bundled with the textbook Neuroscience, and is also sold separately for $29.95 from Sinauer Associates www.sinauer.com.
Also participating in developing Sylvius were Julie Williams, staff members Larry Hawkey and Ann Richards, and faculty colleagues Dale Purves and Nell Cant.