- Created an AIDS vaccine currently in its second human clinical trial. The vaccine initially proved quite successful in nonhuman primate testing and is considered to be a leading candidate in the search for a viable human AIDS vaccine.
- Isolated and characterized T-cells that respond to HIV.
- Identified the first animal model for AIDS-related dementia.
- Discovered the strength of the immune response very early in the course of HIV infection predicts whether HIV eventually will invade the brain.
- Safely and significantly reduced the plasma viral load and also prolonged survival of rhesus macaques severely infected with SIV by blocking programmed death-1 (PD-1), an immune receptor molecule known to inhibit the immune response to chronic viral infections.
- Confirmed CD8+ lymphocytes have an important effect in reducing the level of virus replication in rhesus macaques infected with SIV, a virus closely related to HIV.
- Identified a way some sooty mangabeys' immune cells resist SIV infection, which is helping researchers identify strategies to help HIV-infected individuals cope better with infection.
Cognitive Decline in Aging
- Identified deleterious effects of estrogen on cognitive function.
- Determined spatial memory declines at a greater rate in nonhuman primate males than females, suggesting a species' sex may influence age-related cognitive decline.
- Discovered the first conclusive evidence of Alzheimer’s-like neurofibrillary brain tangles in an aged nonhuman primate.
- Discovered a compound used to diagnose Alzheimer’s disease in humans may also be useful in determining why humans develop the disease and other primates do not.
- Developed a test in nonhuman primates that uses infrared eye tracking to detect mild cognitive impairment (MCI) in humans. Researchers hope the advanced technology will be helpful in predicting the onset of Alzheimer’s disease.
- Developed a new class of compounds, phenyltropanes, which are being tested as candidate medications for treatment of cocaine addiction.
- Identified a new gene called CART (cocaine and amphetamine regulated transcript), whose expression increases with the administration of cocaine.
- Found CART peptides are partially responsible for many of the behavioral changes caused by cocaine and also regulates feeding. Researchers at Yerkes now are studying new ways to treat obesity.
- Determined neurochemical changes in the brain associated with cocaine use also can be triggered by environmental stimuli in the absence of cocaine.
- Determined cocaine's effects in the brain depend upon the context in which the drug is acquired.
Evolution and Behavior
- Discovered capuchin monkeys cooperate to obtain food and share the rewards of their efforts. This behavior has implications for understanding the evolutionary basis of reciprocity, a fundamental feature of human society.
- Showed chimpanzees respond to crowding with powerful coping mechanisms rather than becoming aggressive.
- Learned chimpanzees recognize faces as well as people do.
- Observed similarities between chimpanzee culture and human culture through chimpanzees' ability to adopt social norms, pass down behaviors and traditions to other individuals and to formulate arbitrary sequences of behaviors specific to individual social groups.
- Demonstrated chimpanzees respond empathetically to animated chimpanzees, showing a level of identification with the animations. Understanding why and how chimpanzees connect with animations may help researchers understand why and how humans empathize with others.
- Discovered chimpanzees prefer to follow the example of older, high-status individuals when it comes to solving a problem or adopting a new behavior.
- Identified chimpanzees' contagious yawning is a sign of social connection between the animals. This finding is helping researchers understand empathy in chimpanzees and humans, and may help show how social biases strengthen or weaken empathy.
- Demonstrated chimpanzees have a significant bias for prosocial behavior, which challenged previous findings that humans are an altruistic anomaly.
- Using MRI and PET imaging, Yerkes is working to research and develop discovery isotopes to aid in diagnosing, treating and monitoring diseases with the goal of identifying earlier and more accurately the pharmacological effects of the compounds tested. These findings will be used to determine the potential use of these compounds in diagnosis, treatment and monitoring in humans.
Neurological Basis of Behavior
- Transformed an antisocial mouse into a more social animal by genetically manipulating the distribution of a specific receptor in the brain.
- Discovered a specific neuropeptide in the brain is essential for social recognition in mice.
- Identified unique neural mechanisms involved in mother-infant interactions using non-invasive techniques. These studies provide information on the neural basis of diseases such as autism and schizophrenia.
- Determined the role of steroid hormones, neuropeptides, environmental variables and neuroendocrine mechanisms in primate behavior and reproduction.
- Found a single gene, the vasopressin receptor, is responsible for making promiscuous male meadow voles monogomous.
- Discovered the length of seemingly non-functional DNA, also referred to as junk DNA, may shape social behavior
- Determined tamoxifen induces anxiety-like behavior in female monkeys, which may have implications for humans taking this cancer medication.
- Identified cellular locales where dopamine and glutamate interact within the basal ganglia, the network of neurons that control movement.
- Discovered specific glutamate receptors as targets for the development of new treatments and therapies.
Sensory Motor System Development
- Discovered a dramatic reorganization of brain cells early in life that is vital for normal visual development.
- Characterized the importance of neural circuitry involved in eye growth from birth.
- Determined the visual experience of one eye influences the growth and quality of vision in the other eye.
- Identified the environmental signals that the oculomotor system required in early life to nurture proper eye calibration and the development of normal vision.
- Discovered eye growth can be influenced by environmental factors as late as adolescence.
- Discovered dental pulp stem cells can stimulate growth and generation of several types of neural cells. Findings from this study suggest dental pulp stem cells show promise for use in cell therapy and regenerative medicine, particularly therapies associated with the central nervous system.
- Developed the first transgenic nonhuman primate model of Huntington’s disease (HD), one of the most devastating human neurodegenerative diseases. Development is expected to lead to greater understanding of the underlying biology of HD and to the development of potential therapies.
- Successfully used antibodies to foster long-term acceptance of transplanted organs in mice without immunosuppressive medicine.
- Developed new techniques for precise quantification and typing of T-cell subpopulations as means for measuring the success or failure of a transplanted organ.
- Phase III human clinical trials of the investigational medication belatacept showed the medication is effective in preserving transplanted kidney function while preventing graft rejection.