Paleoneurology Lab at Atapuerca, July 2018
A new PhD student at the paleoneuro lab! María Silva is an archaeologist, and she did a master in human evolution, working on cognitive archaeology and visuospatial integration. Now she will keep on making research in this field, working on visuospatial capacity and experiemental archaeology. She is now fully enrolled in the PhD program at the University of Burgos, Spain. She will integrate concepts in archaeology, cognitive sciences, and psychology, as to investigate issues in brain-body-environment functional relationships. She will work in a joint team with Annapaola, further integrating this group that mixes fossils and behavior. She is also one of the editors of our blog on evolution and prehistory. So, more and more cognition here in this lab!
Two different papers have been published this month on the evolution of the supraorbital anatomy in humans. The first article is on Neanderthal facial morphology, and it was coordinated by Stephen Wroe, of the FEAR lab. Here a comment on the Daily Mail. The second article, by Ricardo Miguel Godinho and coauthors, links supraorbital morphology and social dynamics, and it was commented in a News and Views by Markus Bastir.
Bruner E. & Ogihara N. 2018. Surfin’ endocasts: the good and the bad on brain form. Palaentologia Electronica 21.1.1A: 1-10.
Following bachelor’s work in applied physics at Caltech and a first career as a research engineer at NASA/JPL, Brian Metscher completed his PhD in the then-new interdiscipline of evo-devo at the University of California, Irvine. He did postdoctoral research on the development and evolution of appendages and teeth at The Natural History Museum (London) and Penn State University, and then served five years as an Assistant Professor in southern Indiana. During the summers he carried out research at Yale University and came to the University of Vienna in 2006, to set up the imaging lab in the Department of Theoretical Biology, where he is now Senior Scientist. He helped to establish X-ray microtomography as an essential method for imaging ex vivo biological samples, especially embryos and invertebrates. His lab is developing new and refined sample preparation and imaging methods, with applications including molecular imaging and imaging of specific cells types. He coordinates a MicroCT Methods Forum. Here a brief interview …
What are the basic principles of these methods mixing histology and digital anatomy?
MicroCT provides 3D images of intact samples at resolutions that overlap with what is achieved by light microscopy of sectioned material. Contrast-enhanced X-ray images give only histomorphological information, so microCT images are a powerful complement to traditional histology, which takes advantage of a vast array of stains with different tissue specificities. MicroCT gives a 3D overview and context for more detailed section-based images from histology (and also electron microscope).
So, you stain specimens before microtomographic scan … what about these staining techniques?
The familiar X-ray images of bones or teeth inside the body are possible because the dense calcium-rich materials absorb a lot more X-ray energy than the soft tissues around them – skin, muscle, and internal organs, which are made up mostly of proteins and water. To make soft tissues clearly visible in X-ray images, it helps to add a contrast agent: this can be a suspension of an iodine- or barium-containing liquid injected or swallowed, as is common in clinical radiology examinations. In the case of non-living samples (ex vivo imaging, most of what I do), the sample can be stained with a substance that actually binds to the tissues and has a higher X-ray absorption. The contrast stains used most often are inorganic iodine, phosphotungstic acid, and (less frequently) osmium tetroxide. None of these is specific to any one tissue type, but they do allow the different tissues and structures to be distinguished clearly in the X-ray images.
What kind of expertise, career, and tools are necessary to work in this field?
As with any kind of biological imaging, it is necessary to have a good understanding both of the biological systems under study and of how the imaging systems actually work. So a strong background in microscopy, histology, and image acquisition and analysis is important. And one must always complement one’s own expertise with good working collaborations with partners in other fields.
What is, at present, the most intriguing current challenge?
We would really like to make microCT imaging more tissue- and molecule-specific. Thus I have collaborative projects to test new staining methods and calibrate their functions in microCT images with histological baselines. And my lab is working on refining the antibody imaging method we published a few years ago to make this a more robust and routine method for 3D imaging of gene expression and other molecular patterns in developmental, comparative, and medical-related research.