title: Natural-enriched environments lead to enhanced environmental engagement and altered neurobiological resilience.
abstract: The mammalian brain has evolved in close synchrony with the natural environment; consequently, trends toward disengagement from natural environments in today's industrialized societies may compromise adaptive neural responses and lead to psychiatric illness. Investigations of rodents housed in enriched environments indicate enhanced neurobiological complexity; yet, the origin of these stimuli, natural vs. manufactured, has not been sufficiently explored. In the current study, groups of rats were exposed to one of three environments: (1) a standard environment with only food and water, (2) an artificial-enriched environment with manufactured stimuli and (3) a natural-enriched environment with natural stimuli. Results indicated that, during the dark phase, natural-enriched animals exhibited longer durations interacting with objects than the artificial-enriched group; further, the natural-enriched group engaged in more social behavior than the other two groups. Both enriched groups exhibited less anxiety in response to a novel object but the natural-enriched rats exhibited less anxiety-typical behavior in response to a predator odor than the other groups. Less fos activation in the amygdala was observed in both enriched groups following a water escape task whereas an increase in fos activation in the nucleus accumbens was observed in the natural-enriched animals. Thus, the current findings indicate the potential importance of exposure to complex environments, especially natural-like habitats, in the maintenance of emotional health, perhaps providing a buffer against the emergence of anxiogenic responses.
authors.affiliation: Dept of Psychology, Randolph-Macon College, Ashland, VA 23005, USA. Electronic address: klambert@rmc.edu.
authors.forename: Kelly
authors.initials: K
authors.lastname: Lambert
authors.affiliation: Dept of Psychology, Randolph-Macon College, Ashland, VA 23005, USA; Dept of Psychology, University of Maryland, Baltimore, MD USA.
authors.forename: Molly
authors.initials: M
authors.lastname: Hyer
authors.affiliation: Dept of Psychology, Randolph-Macon College, Ashland, VA 23005, USA.
authors.forename: Massimo
authors.initials: M
authors.lastname: Bardi
authors.affiliation: Dept of Psychology, Randolph-Macon College, Ashland, VA 23005, USA.
authors.forename: Amanda
authors.initials: A
authors.lastname: Rzucidlo
authors.affiliation: Dept of Psychology, Randolph-Macon College, Ashland, VA 23005, USA.
authors.forename: Samantha
authors.initials: S
authors.lastname: Scott
authors.affiliation: Dept of Psychology, Randolph-Macon College, Ashland, VA 23005, USA.
authors.forename: Brennan
authors.initials: B
authors.lastname: Terhune-Cotter
authors.affiliation: Dept of Psychology, Randolph-Macon College, Ashland, VA 23005, USA.
authors.forename: Ashley
authors.initials: A
authors.lastname: Hazelgrove
authors.affiliation: Dept. of Psychology, University of Richmond, Richmond, VA, USA; Biotechnology Program, Universidade Positivo, Curitiba, Brazil.
authors.forename: Ilton
authors.initials: I
authors.lastname: Silva
authors.affiliation: Dept. of Psychology, University of Richmond, Richmond, VA, USA.
authors.forename: Craig
authors.initials: C
authors.lastname: Kinsley
mesh_terms: D000679:Amygdala / Q000378:metabolism; D000818:Animals; D001007:Anxiety / Q000378:metabolism / Q000517:prevention & control; D001522:Behavior, Animal / Q000502:physiology*; D004777:Environment; D005106:Exploratory Behavior / Q000502:physiology*; D006799:Housing, Animal; D007150:Immunohistochemistry; D008297:Male; D023421:Models, Animal; D009473:Neuronal Plasticity; D009483:Neuropsychological Tests; D009714:Nucleus Accumbens / Q000378:metabolism; D016760:Proto-Oncogene Proteins c-fos / Q000378:metabolism; D011897:Random Allocation; D051381:Rats; D055500:Resilience, Psychological; D013315:Stress, Psychological / Q000378:metabolism / Q000517:prevention & control
chemical_list: D016760:Proto-Oncogene Proteins c-fos
keywords: contingency; emotional resilience; enrichment; neuroplasticity; stress