title: Early exposure to noise followed by predator stress in adulthood impairs the rat's re-learning flexibility in Radial Arm Water Maze.
abstract: OBJECTIVE
  This study investigated the cognitive effect of chronic exposure to environmental noise on RAWM performance of juvenile rats, and the ability of adult rats exposed to a novel acute stress to perform in the RAWM as a function of whether or not they were exposed to environmental noise as juveniles.
  
  
  METHODS
  We examined the consequences of exposure to noise during the juvenile-early periadolescent period on adulthood stress response by assessing cognitive performance in the RAWM. Male rats were exposed to environmental noise during the childhood-prepubescent period (21-35 PND), and their RAWM performance was tested at the end of the exposure to noise, and then again two months later when they had to cope with a new stressful event. RAWM execution included a 3-day training phase and a reversal learning phase on day 4. Escape latency, reference memory errors and working memory errors were compared between experimental and control groups. In addition, body weight gain and serum corticosterone levels were evaluated.
  
  
  RESULTS
  Stressed rats demonstrated spatial impairment, as evidenced by poor execution on day 4. This effect was significantly noticeable in the doubly stressed group. Noise annoyance was evidenced by reduced body weight gain and increased serum corticosterone levels.
  
  
  CONCLUSIONS
  Our results suggest that environmental noise may produce potent stress-like effects in developing subjects that can persist into adulthood, affecting spatial learning abilities. This cognitive impairment may restrict the subject's ability to learn under a new spatial configuration.
authors.affiliation: Departamento de Neurociencias, CUCS, Universidad de Guadalajara, Guadalajara, Mexico.
authors.forename: Fernando
authors.initials: F
authors.lastname: Jauregui-Huerta
authors.forename: Yaveth
authors.initials: Y
authors.lastname: Ruvalcaba-Delgadillo
authors.forename: Joaquin
authors.initials: J
authors.lastname: Garcia-Estrada
authors.forename: Alfredo
authors.initials: A
authors.lastname: Feria-Velasco
authors.forename: Rodrigo
authors.initials: R
authors.lastname: Ramos-Zuñiga
authors.forename: Oscar
authors.initials: O
authors.lastname: Gonzalez-Perez
authors.forename: Sonia
authors.initials: S
authors.lastname: Luquin
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D001835:Body Weight; D008297:Male; D018782:Maze Learning / Q000502:physiology*; D009622:Noise; D051381:Rats; D017208:Rats, Wistar; D012193:Reversal Learning / Q000502:physiology*; D013037:Spatial Behavior / Q000502:physiology; D013312:Stress, Physiological / Q000502:physiology*; D013315:Stress, Psychological / Q000503:physiopathology*