title: The influence of complex and threatening environments in early life on brain size and behaviour.
abstract: The ways in which challenging environments during development shape the brain and behaviour are increasingly being addressed. To date, studies typically consider only single variables, but the real world is more complex. Many factors simultaneously affect the brain and behaviour, and whether these work independently or interact remains untested. To address this, zebrafish (Danio rerio) were reared in a two-by-two design in housing that varied in structural complexity and/or exposure to a stressor. Fish experiencing both complexity (enrichment objects changed over time) and mild stress (daily net chasing) exhibited enhanced learning and were less anxious when tested as juveniles (between 77 and 90 days). Adults tested (aged 1 year) were also less anxious even though fish were kept in standard housing after three months of age (i.e. no chasing or enrichment). Volumetric measures of the brain using magnetic resonance imaging (MRI) showed that complexity alone generated fish with a larger brain, but this increase in size was not seen in fish that experienced both complexity and chasing, or chasing alone. The results highlight the importance of looking at multiple variables simultaneously, and reveal differential effects of complexity and stressful experiences during development of the brain and behaviour.
authors.affiliation: Department of Biology, Pennsylvania State University-Altoona, Altoona, PA, USA Center for Brain, Behavior, and Cognition, Pennsylvania State University, University Park, PA, USA Department of Ecosystem Science and Management, Pennsylvania State University, University Park, PA, USA ocg102@psu.edu.
authors.forename: C
authors.identifier: 0000-0003-2771-548X
authors.initials: C
authors.lastname: DePasquale
authors.affiliation: Huck Institutes of the Life Sciences, Pennsylvania State University, University Park, PA, USA Department of Bioengineering, Pennsylvania State University, University Park, PA, USA.
authors.forename: T
authors.initials: T
authors.lastname: Neuberger
authors.affiliation: Department of Biology, Pennsylvania State University, University Park, PA, USA.
authors.forename: A M
authors.initials: AM
authors.lastname: Hirrlinger
authors.affiliation: Center for Brain, Behavior, and Cognition, Pennsylvania State University, University Park, PA, USA Department of Ecosystem Science and Management, Pennsylvania State University, University Park, PA, USA Department of Biology, Pennsylvania State University, University Park, PA, USA.
authors.forename: V A
authors.initials: VA
authors.lastname: Braithwaite
mesh_terms: D000818:Animals; D001007:Anxiety; D001522:Behavior, Animal; D001921:Brain / Q000254:growth & development*; D004777:Environment; D006799:Housing, Animal; D013315:Stress, Psychological; D015027:Zebrafish / Q000254:growth & development*
keywords: anxiety; behavioural plasticity; brain size; environmental enrichment; spatial learning; zebrafish (Danio rerio)
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