Sally P. Mendoza - US grants

psychology; Primates; Mammalia; behavioral /social science research tag;

Significance Chronic social and psychological stressors, prevalent in modern society, are important determinants of health and welfare. This research investigates, in highly social primates the consequences of social and environmental perturbations that challenge restoration of homeostasis and lead to lengthy periods of altered pituitary-adrenal regulation. Objectives This is a new program of research that is designed to evaluate the cognitive, immunological, and neurobiological consequences of stressors that produce chronic elevations and chronic reductions in pituitary-adrenal activity in New World monkeys. Results Much of the immunological and neurobiological research in chronic stress has relied on pharmacological manipulation of glucorticoid levels. The assumption of this research, that it is stress-induced elevations in glucocorticoids that account for health risks associated with stress, has rarely been tested directly. Our research will capitalize on a broad-based understanding of the social interactions of New World monkeys and the evidence that alterations in the social situations of these monkeys provides naturalistic models of chronic stress. We have identified two simple social manipulations that result in long-term disruption of pituitary-adrenal regulation. Mate separation in titi monkeys produces long-term elevations in cortisol; group formation in squirrel monkeys produces long-term reductions in cortisol. Comparison of the two species affords a unique opportunity to ask whether chronic stress subsumes multiple distinct syndromes, each associated with its own symptoms and risks. Future Directions We will begin detailed comparison of cognitive performance (using computer-assisted behavioral testing) and immunological competence in animals with chronically elevated or reduced glucocorticoids.. Plans also include comparison of hippocampal structure and function in animals that have been subjected to chronic stress.

psychology; behavioral /social science research tag; Mammalia;

psychology; behavioral /social science research tag; Mammalia;

DESCRIPTION (provided by applicant): Social relationships among primates include extensive physical contact between individual members of the relationship. The propensity to seek contact with individuals with which a strong relationship has been established is exemplified in the extreme by the South American titi monkey. These monogamous primates spend up to 90% of their day in physical contact with other members of their family group. Much of the contact between family members is passive -animals sit side-by-side with their lateral surface in close contact with another monkey. A unique aspect of this social contact is tail-twining. As animals sit in passive contact, they swing their tails laterally until it contacts the other animal's tail and then the tails tightly wrap around one another. When multiple animals are sitting together they wrap all of their tails in a single tail- twine. Active contact between titi monkeys includes grooming, grasping an arm to pull adjacent animals closer, nuzzling the chest or mouth of another group member, and, for males, bimanual clasping of the female's haunches during copulation. The proposed research will examine the role of several somatosensory cortical areas we believe are involved in the expression and maintenance of affective social relationships. We will examine information processing and the functional organization of somatosensory areas in anterior and posterior parietal cortex using multiunit recording techniques and neuroanatomical tracing techniques. We expect that representation of body parts, involved in social contact, will be magnified compared to other primates. We will selectively lesion, using aspiration techniques, different cortical fields in animals from well-established social groups. We will then monitor changes in social behavior and social motivation associated with the loss of a specific field or body part representation therein. These studies are unique in that they take advantage of an overt behavior, directly mediated by the somatosensory system, to examine the role of cortical mechanisms involved in discrete social interactions.

behavioral /social science research tag

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. The primary goal of this project is to develop and test non-invasive imaging methods, including dopamine receptor ligands, for non-human primates. The secondary goal of this project is to test behavioral correlations (ex. sucrose consumption) with these receptor measures.