Project Summary: Neurobiology of the Naked Mole-Rat
Intellectual merit: Naked mole-rats have an unusual lifestyle in that they combine a fully subterranean existence, extreme sociality, and a proclivity for living in large numbers. Spending their entire lives in crowded burrows where many individuals share a limited air supply, these animals have developed an unusual resilience to the challenges of breathing exceptionally low levels of oxygen and exceptionally high levels of carbon dioxide. Initial studies have revealed numerous extraordinary features of naked mole-rat neurobiology that are hypothesized to be adaptations for living under these challenges. Some of these features protect the brain from low O2, while others promote peripheral nerve insensitivity to CO2-induced acidosis. Intriguingly, the same traits are also seen in neonatal mammals, prompting the current hypothesis that naked mole-rats employ a form of arrested development (neoteny) to protect their nervous system from chronic low O2/high CO2, a protection lost during development in other mammals. The goals of the project now are to better understand the nature of arrested development and associated phenomena, including the underlying basis of hypoxia-induced torpor, persistence of neonatal features of brain physiology into adulthood, and the presence of extra-neuronal sodium channels in peripheral nerves. Another major goal is to determine if other species of African mole-rats display these extraordinary nervous system traits in order to determine if these putative adaptations evolved independently multiple times. The project will rely on a systems neurobiology approach, which will include behavioral, physiological, anatomical, and molecular experiments with a strong emphasis on comparative data from closely- and distantly- related species that also vary in similarity of lifestyle to that of naked mole-rats. The results of the proposed studies could transform our understanding of nervous system adaptations to environmental and social conditions, revitalize the comparative approach in neurobiology, and promote a wider appreciation for evolutionary neuroscience in students and the public at large.
Broader impacts: This project will have a broad impact on science and education in several ways. The project will provide training opportunities for graduate students. It will also support the work of undergraduates interested in systems neurobiology, and in particular, students of under-represented groups. During the previous grant, this project mentored 19 undergraduate women including 4 REU students (one African American, four Latin Americans), as well as an African American student from UIC’s Summer Research Opportunities Program for underrepresented students (SROP), 23 undergraduates in total. Continued funding will allow for continued mentorship, specifically targeting SROP students, as well as students from the Ronald E. McNair Program. A routine part of the research experience is presenting posters at UIC’s Undergraduate Research Symposium and the Chicago Area Undergraduate Research Symposium. The project also will impact students in the classroom, as the naked mole-rats are directly used in laboratory exercises and independent student research projects in two Biology courses (Animal Behavior and Neuroethology and Cellular Neurobiology Laboratory). Also, data from the research is integrated into three additional courses (Animal Physiological Systems, Neuroscience Methods, and Neuroscience). Members of the project also use data from the project to educate the public by acting as Information Specialist volunteers at Chicago’s Lincoln Park Zoo, which is a free-admission, city zoo. The naked mole-rat display draws large numbers of both children and adults and provides a good platform for casual dissemination of information about systems neurobiology focusing on the naked mole-rat as a model. Finally, this species’ combination of interesting neurobiological traits, bizarre appearance (bald and bucktoothed), and intriguing name (naked) has attracted attention from the mainstream media, providing a means for bringing neurobiology to the public. For example, the cover story of the June 2012 issue of The Scientist featured the naked mole-rat, and that story was the 2nd most popular of 2012. It is urgent that we take advantage of the current momentum in rising popularity of this model so we can continue engaging the public and promoting the idea that science is cool.