While several aspects of “normal” life have been put on hold during the pandemic, that hasn’t occurred with research at Des Moines University. Case in point is a significant set of research on the brains of chimpanzees and wild and domestic canids that several DMU faculty, students and other international researchers collaborated on.
Muhammad Spocter, Ph.D., associate professor of anatomy at DMU, was lead author of a paper published in the Proceedings of the Royal Society in September, titled “Reproducibility of Leftward Planum Temporale Asymmetries in Two Genetically Isolated Populations of Chimpanzees (Pan troglodytes).” It describes research on the asymmetries in cortical language areas, particularly the planum temporale, in the brains of chimpanzees, one of humans’ closest genetic ancestors.
“Humans are historically thought of as being unique in having a complex language system that is processed in the left hemisphere of the brain. Our research conclusively shows that one of our closest living relatives, the common chimpanzees, also exhibit this pattern of hemispheric dominance along with similar genetic underpinnings,” Dr. Spocter says. “This work is important because identifying the neuroanatomical signature of human language, provides us with a narrowing of the search space to help target the mechanisms responsible for deficiencies in human language and speech.”
This research also underscores the value of studying organisms beyond the dominant so-called model species, the mouse, the nematode worm, the fruit fly and the thale cress (a small flowering plant). While research using these species has generated significant basic knowledge and medical progress, they are limited in their ability to resolve the complexity of the primate nervous system as well as the complex biosocial/biocultural attributes that have a bearing on human brain development.
“Our work is specifically aimed at breaking with the traditional set of model organisms. By using comparative behavioral as well as phylogenetic data, we are able to better inform our choice of model species,” Dr. Spocter says. “For instance, over the last few years we have described the comparative cortical anatomy of wild and domestic canids, the family which includes domestic dogs and other wolf or fox like animals. This work is guided by comparative behavioral data which has indicated that dogs possess a unique ability to understand human communicative cues, which is not found in wild canids. By using a comparative framework, we are able to identify the neural structures which support the underlying behavior and have been shaped through domestication.
“These studies highlight the diversity in the mammalian brain and that similarities in structure or function of the nervous system may arise through either shared ancestry – i.e., a shared genetic underpinning – or through similar environments, resulting in a convergence in form and function,” he adds. “The insight gained from these comparative studies helps inform our understanding of sociocognitive deficits in humans, such as autism spectrum disorder, but also have a bearing on the efficacy of possible pharmacological interventions when translating those treatments from the basic science benchtop to the bedside of our patients.”
Dr. Spocter, along with other members of the DMU community (in bold), generated this set of papers about the canid brain:
- Grewal, J.S., Gloe, T., Hegedus, J., Bitterman, K., Billings, B., Chengetanai, S., Bentil, S., Ng, J., Wang, V., Tang, C.C., Geletta, S., Wicinski, B., Bertelson, M., Tendler, B.C., Mars, R., Aquirre, G.K., Rusbridge, C., Hof, P.R., Sherwood, C.C., Manger, P.R., & Spocter, M.A. (2020). Brain gyrification in wild and domestic canids: Has domestication changed the gyrification index in domestic dogs? Journal of Comparative Neurology.
- Chengetania, S., Tenley, J., Bertelson, M,F., Hard, T., Bhagwandin, A., Haagensen, M., Tang, C., Wicinski, B., Hof, P.R., Manger, P.R., & Spocter, M.A. (2020). The brain of the African wild dog. I. Anatomy, architecture and volumetrics. Journal of Comparative Neurology.
- Chengetania, S., Bhagwandin, A., Bertelson, M.F., Hard, T., Hof, P.R., Spocter, M.A., & Manger, P.R. (2020). The brain of the African wild dog. II. The olfactory system. Journal of Comparative Neurology.
- Chengetania, S., Bhagwandin, A., Bertelson, M.F., Hard, T., Hof, P.R., Spocter, M.A., & Manger, P.R. (2020). The brain of the African wild dog. III. The auditory system. Journal of Comparative Neurology.
- Chengetania, S., Bhagwandin, A., Bertelson, M.F., Hard, T., Hof, P.R., Spocter, M.A., & Manger, P.R. (2020). The brain of the African wild dog. IV. The visual system. Journal of Comparative Neurology.
- Nguyen, V., Uchida, R., Warling, A., Sloan, L.J., Dodelson, C., Shin, R., Wicinski, B., Bitterman, K., Bertelsen, M.F., Stimpson, C.D., Schall, M., Hof, P.R., Sherwood, C.C., Manger, P.R., Spocter, M.A., & Jacobs, B. (2020). Comparative neocortical neuromorphology in felids: African lion (Panthera leo), African leopard (Panthera pardus pardus) and cheetah (Acinonyx jubatus). Journal of Comparative Neurology.
Dr. Spocter’s laboratory also turned out several collaborative encyclopedic entries during the pandemic, to which other DMU faculty and students contributed. The researchers’ entry on evolutionary medicine was selected by Springer Nature as important to researchers working on SARS-CoV-2, the virus that causes COVID-19, and is now freely available for the duration of the pandemic. Authors of that work from DMU included Kaitlyn Finneran, an osteopathic medical student; Teresa Aoki, M.D., associate professor of family and internal medicine; and Maria Barnes, Ph.D., assistant professor of biochemistry and nutrition.
“In this paper, using insight gained from evolutionary theory we made a postulate about the likely evolution of virulence of this virus and its differential effects on children,” Dr. Spocter says. “The prediction seems to hold out so far as we see evidence for larger viral loads in kids than adults, affecting transmission rates and suggesting that the virulence of this virus is likely to increase if a vaccine is not forthcoming.
“The importance of a comparative approach is further highlighted by our developing understanding of the cross-species effects of SARS-CoV-2 infection. There is growing evidence that dogs and other canids seem to have a natural resistance to the SARS-CoV-2 infection, while felids – i.e., domestic cats and other wild cat-like species – show moderate susceptibility to the virus and seem to develop similar clinical signs,” he adds. “Similarly, mink and ferrets also show high susceptibility to SARS-CoV-2 infection, with millions of these animals dying as a result of human handlers inadvertently transferring the virus into captive animal populations, bringing the fur industry to a halt across Europe and parts of the U.S. This difference in susceptibility is another example of why looking beyond the traditional list of model organisms is important to biomedical science.
“One last point, which highlights the intersection of our work on the canid brain and how this basic science can inform medicine or help with diagnosis, is growing evidence that dogs can be trained successfully to sniff out COVID-19, with an apparent 100 percent success rate. This evidence has now been put into use at certain airports in Europe,” says Dr. Spocter. “This ability of dogs is undoubtedly linked to the keen olfactory abilities of all the canids, something which we recently explored in our study of the olfactory system in the African wild dog. Here we showed through quantitative comparison of the olfactory bulb (and underlying glomeruli) that the African wild dog possesses an enhanced ability for processing a broad range of odorants, something which it uses in its natural environment in the African savanna. One could only imagine the possibilities of how such a keen sensory ability could help with the early detection of other human diseases.”
The encyclopedic entries are as follows, with names of DMU researchers in bold:
- Finneran, K., Aoki, T., Barnes, M. J., & Spocter, M.A. (2020). Evolutionary Medicine. In: T.K. Shackelford, & V.A. Weekes-Shackelford (Eds.), Encyclopedia of Evolutionary Psychological Science. New York, NY: Springer Cham.
- Braken, E., Billings, B.K., Barnes, M. J., & Spocter, M.A. (2020). The evolution of tool use. In: T.K. Shackelford, & V.A. Weekes-Shackelford (Eds.), Encyclopedia of Evolutionary Psychological Science. New York, NY: Springer Cham.
- Spocter, M.A (2020). Adaptation. In: T.K. Shackelford, & V.A. Weekes-Shackelford (Eds.), Encyclopedia of Evolutionary Psychological Science. New York, NY: Springer Cham.
- Haas, J., Hass, R., Spocter, M.A., & de Sousa, A.A. (2020). Human Visual Neuroscience. In: T.K. Shackelford, & V.A. Weekes-Shackelford (Eds.), Encyclopedia of Evolutionary Psychological Science. New York, NY: Springer Cham.