title: Network Patterns Associated with Navigation Behaviors Are Altered in Aged Nonhuman Primates.
abstract: The ability to navigate through space involves complex interactions between multiple brain systems. Although it is clear that spatial navigation is impaired during aging, the networks responsible for these altered behaviors are not well understood. Here, we used a within-subject design and [18F]FDG-microPET to capture whole-brain activation patterns in four distinct spatial behaviors from young and aged rhesus macaques: constrained space (CAGE), head-restrained passive locomotion (CHAIR), constrained locomotion in space (TREADMILL), and unconstrained locomotion (WALK). The results reveal consistent networks activated by these behavior conditions that were similar across age. For the young animals, however, the coactivity patterns were distinct between conditions, whereas older animals tended to engage the same networks in each condition. The combined observations of less differentiated networks between distinct behaviors and alterations in functional connections between targeted regions in aging suggest changes in network dynamics as one source of age-related deficits in spatial cognition.
  
  
  
  We report how whole-brain networks are involved in spatial navigation behaviors and how normal aging alters these network patterns in nonhuman primates. This is the first study to examine whole-brain network activity in young or old nonhuman primates while they actively or passively traversed an environment. The strength of this study resides in our ability to identify and differentiate whole-brain networks associated with specific navigational behaviors within the same nonhuman primate and to compare how these networks change with age. The use of high-resolution PET (microPET) to capture brain activity of real-world behaviors adds significantly to our understanding of how active circuits critical for navigation are affected by aging.
authors.affiliation: Evelyn F. McKnight Brain Institute and.|Division of Neural Systems, Memory and Aging, University of Arizona, Tucson, Arizona 85724.|California National Primate Research Center, Davis, California 95616.
authors.forename: James R
authors.identifier: 0000-0002-0166-1252
authors.initials: JR
authors.lastname: Engle
authors.affiliation: California National Primate Research Center, Davis, California 95616.|Department of Psychiatry and Behavioral Sciences, University of California-Davis, Sacramento, California 95817, and.
authors.forename: Christopher J
authors.identifier: 0000-0001-6865-7429
authors.initials: CJ
authors.lastname: Machado
authors.affiliation: California National Primate Research Center, Davis, California 95616.
authors.forename: Michele R
authors.identifier: 0000-0001-7848-877X
authors.initials: MR
authors.lastname: Permenter
authors.affiliation: California National Primate Research Center, Davis, California 95616.
authors.forename: Julie A
authors.identifier: 0000-0003-2652-7954
authors.initials: JA
authors.lastname: Vogt
authors.affiliation: Evelyn F. McKnight Brain Institute and.|Division of Neural Systems, Memory and Aging, University of Arizona, Tucson, Arizona 85724.
authors.forename: Andrew P
authors.identifier: 0000-0002-5470-237X
authors.initials: AP
authors.lastname: Maurer
authors.affiliation: California National Primate Research Center, Davis, California 95616.
authors.forename: Alicia M
authors.identifier: 0000-0003-1462-8483
authors.initials: AM
authors.lastname: Bulleri
authors.affiliation: Evelyn F. McKnight Brain Institute and carol@nsma.arizona.edu.|Division of Neural Systems, Memory and Aging, University of Arizona, Tucson, Arizona 85724.|California National Primate Research Center, Davis, California 95616.|Departments of Psychology, Neurology, and Neuroscience, University of Arizona, Tucson, Arizona 85721.
authors.forename: Carol A
authors.initials: CA
authors.lastname: Barnes
mesh_terms: D000222:Adaptation, Physiological / Q000502:physiology; D000375:Aging / Q000502:physiology*; D000818:Animals; D001522:Behavior, Animal / Q000502:physiology*; D001921:Brain / Q000502:physiology*; D001931:Brain Mapping; D005260:Female; D006801:Humans; D008253:Macaca mulatta; D008297:Male; D009415:Nerve Net / Q000502:physiology*; D009434:Neural Pathways / Q000502:physiology; D009473:Neuronal Plasticity / Q000502:physiology*; D065854:Spatial Navigation / Q000502:physiology*
keywords: aging; brain circuits; spatial cognition