title: Defensive behaviors and prosencephalic neurogenesis in pigeons (Columba livia) are affected by environmental enrichment in adulthood.
abstract: Neurogenesis in the adult brain appears to be phylogenetically conserved across the animal kingdom. In pigeons and other adult non-oscine birds, immature neurons are observed in several prosencephalic areas, suggesting that neurogenesis may participate in the control of different behaviors. The mechanisms controlling neurogenesis and its relevance to defensive behaviors in non-oscine birds remain elusive. Herein, the contribution of the environment to behavior and neurogenesis of pigeons was investigated. Adult pigeons (Columba livia, n = 6/group), housed in standard (SE) or enriched environment (EE) for 42 days, were exposed to an unfamiliar environment (UE) followed by presentation to a novel object (NO). Video recordings of UE+NO tests were analyzed and scored for latency, duration and frequency of angular head movements, peeping, grooming, immobility and locomotion. Twenty-four hours later, pigeons were submitted to the tonic immobility test (TI) and number of trials for TI and TI duration were scored, followed by euthanasia 2 h later. Brains were immunohistochemically processed to reveal doublecortin (DCX), a marker for newborn neurons. Compared to those housed in SE, the pigeons housed in EE responded to a NO with more immobility. In addition, the pigeons housed in EE presented longer TI, more DCX-immunoreactive (DCX-ir) cells in the hippocampus and fewer DCX-ir cells in the lateral striatum than those housed in SE. There was no correlation between the number of DCX-ir cells and the scores of immobility in behavioral tests. Together, these data suggest that enrichment favored behavioral inhibition and neurogenesis in the adult pigeons through different, parallel mechanisms.
authors: Department of Physiological Sciences, CCB, Federal University of Santa Catarina, Florianópolis, SC, 88040-900, Brazil. fmelleu@gmail.com.
authors: F F
authors: FF
authors: Melleu
authors: Department of Physiological Sciences, CCB, Federal University of Santa Catarina, Florianópolis, SC, 88040-900, Brazil.
authors: M V
authors: MV
authors: Pinheiro
authors: Department of Physiological Sciences, CCB, Federal University of Santa Catarina, Florianópolis, SC, 88040-900, Brazil.
authors: C
authors: C
authors: Lino-de-Oliveira
authors: Department of Physiological Sciences, CCB, Federal University of Santa Catarina, Florianópolis, SC, 88040-900, Brazil.|Institute of Biomedical Engineering, EEL-CTC, Federal University of Santa Catarina, Florianópolis, SC, 88040-900, Brazil.
authors: J
authors: J
authors: Marino-Neto
mesh_terms: D000818:Animals; D001522:Behavior, Animal; D010856:Columbidae; D000089622:Doublecortin Domain Proteins; D004777:Environment; D005260:Female; D008297:Male; D008869:Microtubule-Associated Proteins / Q000378:metabolism; D055495:Neurogenesis; D009474:Neurons / Q000166:cytology / Q000378:metabolism; D009479:Neuropeptides / Q000378:metabolism; D016548:Prosencephalon / Q000166:cytology / Q000502:physiology*
chemical_list: D000089622:Doublecortin Domain Proteins; D008869:Microtubule-Associated Proteins; D009479:Neuropeptides
keywords: Adult neurogenesis; Avian; Defensive behavior; Environmental enrichment; Hippocampus