Chronic oxytocin administration in older men modulates functional connectivity during animacy perception
Pedro A. Valdes-Hernandez,
Rebecca Polk,
Marilyn Horta,
Ian Frazier,
Eliany Perez,
Marite Ojeda,
Eric Porges,
Yenisel Cruz-Almeida,
David Feifel,
Natalie C. Ebner
Affiliations
Pedro A. Valdes-Hernandez
Department of Psychology, College of Liberal Arts and Sciences, University of Florida, FL, USA; Department of Community Dentistry & Behavioral Sciences, College of Dentistry, University of Florida, FL, USA; Pain Research and Intervention Center of Excellence, University of Florida, FL, USA; Corresponding authors at: Community Dentistry & Behavioral Science, College of Dentistry, Pain Research and Intervention Center of Excellence, University of Florida, P.O. Box 112250, Gainesville, FL 32611, USA (A. Valdes-Hernandez). Department of Psychology, College of Liberal Arts and Sciences, Pain Research and Intervention Center of Excellence, University of Florida, P.O. Box 112250, Gainesville, FL 32611, USA (N.C. Ebner).
Rebecca Polk
Department of Psychology, College of Liberal Arts and Sciences, University of Florida, FL, USA
Marilyn Horta
Department of Psychology, College of Liberal Arts and Sciences, University of Florida, FL, USA
Ian Frazier
Department of Psychology, College of Liberal Arts and Sciences, University of Florida, FL, USA
Eliany Perez
Department of Psychology, College of Liberal Arts and Sciences, University of Florida, FL, USA
Marite Ojeda
Department of Psychology, College of Liberal Arts and Sciences, University of Florida, FL, USA
Eric Porges
Department of Clinical and Health Psychology, College of Public Health and Health Professions, University of Florida, FL, USA
Yenisel Cruz-Almeida
Department of Community Dentistry & Behavioral Sciences, College of Dentistry, University of Florida, FL, USA; Pain Research and Intervention Center of Excellence, University of Florida, FL, USA
David Feifel
Department of Aging and Geriatric Research, Institute on Aging, University of Florida, FL, USA
Natalie C. Ebner
Department of Psychology, College of Liberal Arts and Sciences, University of Florida, FL, USA; Pain Research and Intervention Center of Excellence, University of Florida, FL, USA; Department of Clinical and Health Psychology, College of Public Health and Health Professions, University of Florida, FL, USA; Department of Psychiatry, University of California, San Diego, CA, USA; Corresponding authors at: Community Dentistry & Behavioral Science, College of Dentistry, Pain Research and Intervention Center of Excellence, University of Florida, P.O. Box 112250, Gainesville, FL 32611, USA (A. Valdes-Hernandez). Department of Psychology, College of Liberal Arts and Sciences, Pain Research and Intervention Center of Excellence, University of Florida, P.O. Box 112250, Gainesville, FL 32611, USA (N.C. Ebner).
While aging is associated with social-cognitive change and oxytocin plays a crucial role in social cognition, oxytocin’s effects on the social brain in older age remain understudied. To date, no study has examined the effects of chronic intranasal oxytocin administration on brain mechanisms underlying animacy perception in older adults. Using a placebo-controlled, randomized, double-blinded design in generally healthy older men (mean age (SD) = 69(6); n = 17 oxytocin; n = 14 placebo), this study determined the effects of a four-week intranasal oxytocin administration (24 international units/twice a day) on functional MRI (fMRI) during the Heider-Simmel task. This passive-viewing animacy perception paradigm contains video-clips of simple shapes suggesting social interactions (SOCIAL condition) or exhibiting random trajectories (RANDOM condition). While there were no oxytocin-specific effects on brain fMRI activation during the SOCIAL compared to the RANDOM condition, pre-to-post intervention change in the SOCIAL-RANDOM difference in functional connectivity (FC) was higher in the oxytocin compared to the placebo group in a network covering occipital, temporal, and parietal areas, and the superior temporal sulcus, a key structure in animacy perception. These findings suggest oxytocin modulation of circuits involved in action observation and social perception. Follow-up analyses on this network’s connections suggested a pre-to-post intervention decrease in the SOCIAL-RANDOM difference in FC among the placebo group, possibly reflecting habituation to repeated exposure to social cues. Chronic oxytocin appeared to counter this process by decreasing FC during the RANDOM and increasing it during the SOCIAL condition. This study advances knowledge about oxytocin intervention mechanisms in the social brain of older adults.
