A walk-in freezer in Science and Engineering Hall houses more than 650 mammalian brains--from tigers, elephants, giraffes, gorillas and lots of chimpanzees.
Chet Sherwood, a professor of anthropology at the George Washington University, oversees the collection, which comprises the brains of animals that have died from natural causes at zoos and research centers. The light pink organs are key to understanding what makes human neurobiology unique, Dr. Sherwood said.
Among the animals represented in the assortment, chimpanzees may be the most essential research subjects. Sharing more than 98 percent of their DNA with humans, they are our closest living relatives. That makes their brains ideal for studying recently evolved neurodevelopmental and neurodegenerative disorders, like autism, Alzheimer's disease and schizophrenia.
"The fact that chimpanzees are the closest living relatives of humans puts them in a really unique position to help us understand the evolutionary context of neurobiological traits that are elaborated in our species," said Dr. Sherwood, a member of the Center for the Advanced Study of Human Paleobiology, the GW Institute for Neuroscience and director of the GW Mind-Brain Institute.
For the past two decades, chimpanzees housed in National Primate Research Centers have been the subjects of intensive cognitive and behavioral research studies. Recently, however, the National Institutes of Health stopped breeding chimpanzees and significantly reduced their use in NIH-funded biomedical research. So opportunities for scientists to take advantage of these rich resources are fading.
Dr. Sherwood and his colleagues saw this as an opportunity to gather and organize longitudinal data from years of NIH-funded chimpanzee studies, as well as to develop new tools for deeper analysis, in an effort to promote the wider study of chimpanzee brains for future generations.
"As chimpanzees are retired out of research, the captive population is declining," Dr. Sherwood said. "So this is a really critical and unique time to invest in preserving as much information as possible about chimpanzee brains for the research community."
A new grant from the NIH--totaling around $1 million--will allow Dr. Sherwood and his research team to do just that. The funding will support the creation of the first National Chimpanzee Brain Resource that will be based at GW, Georgia State and Emory universities.
GW will serve as a brain repository, where scientists can request tissue samples from the university's collection to be sent to their own labs. The project team also will make available their assemblage of high-resolution MRI scans of chimpanzee brains along with observational data collected from studies on chimpanzees' motor, social and cognitive skills. With this information, the researchers plan to create an online, searchable database that scientists can easily access. They also will build a detailed chimpanzee brain atlas and gene-expression map that can be used for research on the molecular pathways related to cognition and brain disease. (There are no chimpanzees housed at GW.)
"Right now there is a very small community of people who are focused on chimpanzee neuroscience research," Dr. Sherwood said. "We are trying to catalyze the use of what we view to be incredibly valuable, scientifically interesting materials that are underutilized."
Chimpanzee brain tissue and data have an expansive range of research possibilities, he said. Dr. Sherwood's own lab uses brain scans to understand topics like the role of genetics in shaping brain anatomy and the neurobiological basis of human language and social learning.
His latest project--funded by a $1 million INSPIRE award from the National Science Foundation--will use post-mortem MRI images, brain tissue, behavioral observations and studies of genetic variation to examine differences in vocal learning and sound-symbol associations among chimpanzees.
Chimpanzees show much variation in facial motor control that allows some, but not others, to learn new vocalizations. To understand these neurobiological differences, Dr. Sherwood and Brenda Bradley, an associate professor of anthropology, will use genomic analyses to determine how certain genes play a role in establishing brain circuitry critical for communication skills in primates. The researchers say their results have the potential to better understand language and learning abilities in both humans and chimpanzees.
"If you want to start thinking about the evolution of language in humans, you need this broader biological context, which studying the brains of chimpanzees can offer," Dr. Sherwood said.
"That is what the NIH has invested in us to do--to make it easier for all neuroscientists to incorporate data from chimpanzee studies in their research if they wish to do so."