Environmental enrichment improves cognitive deficits in Spontaneously Hypertensive Rats (SHR): Relevance for Attention Deficit/Hyperactivity Disorder (ADHD)

• Published in: Progress in neuro-psychopharmacology & biological psychiatry Vol. 33; no. 7; pp. 1153 - 1160
• Main Authors: Pamplona, Fabrício A., Pandolfo, Pablo, Savoldi, Robson, Prediger, Rui Daniel S., Takahashi, Reinaldo N.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier Inc 01.10.2009; Elsevier
• Subjects: Age Factors; Analysis of Variance; Animals; Animals, Newborn; Arterial hypertension. Arterial hypotension; Attention Deficit Disorder with Hyperactivity - complications; Attention deficit disorders. Hyperactivity; Attention Deficit/Hyperactivity Disorder (ADHD); Biological and medical sciences; Blood and lymphatic vessels; Blood Pressure - genetics; Cardiology. Vascular system; Child clinical studies; Cognition Disorders - etiology; Cognition Disorders - therapy; Disease Models, Animal; Environment; Environmental enrichment; Exploratory Behavior - physiology; Maze Learning - physiology; Medical sciences; Morris water maze; Neuropharmacology; Object recognition; Pharmacology. Drug treatments; Psychology. Psychoanalysis. Psychiatry; Psychopathology. Psychiatry; Rats; Rats, Inbred SHR; Rats, Wistar; Recognition (Psychology); Social Behavior; Social recognition; Space Perception - physiology; Spontaneously Hypertensive Rats (SHR); WIS; EE; ADHD; SE; Morris water maze; Attention Deficit/Hyperactivity Disorder (ADHD); Environmental enrichment; Spontaneously Hypertensive Rats (SHR); Social recognition; SHR; Object recognition; Hypertension; Cognitive disorder; Rat; Rodentia; Cardiovascular disease; Space perception; Stimulating environment; Vertebrata; Mammalia; Animal; Attention disorder with hyperactivity; Perceptive learning; Recognition; Public health
• ISSN: 0278-5846; 1878-4216
• DOI: 10.1016/j.pnpbp.2009.06.012

The interaction between genes and environment seems to be relevant for the development of Attention Deficit/Hyperactivity Disorder (ADHD), one of the most prevalent childhood psychiatric diseases. The occurrence of ADHD is typically associated with poor academic performance, probably reflecting learning difficulties and/or cognitive impulsiveness. The inbred Spontaneously Hypertensive Rats (SHR) strain has often been considered as an animal model of ADHD, since they ‘naturally’ display the main ADHD symptomatology. Although pharmacological agents improve SHR's cognitive deficits, little is known about the involvement of environmental factors in SHR disabilities and to what extent ‘protective’ non-pharmacological factors may be considered as strategy for ADHD prevention. Here we investigated whether the rearing environment during neurodevelopment may counteract later cognitive deficits presented by adult SHR. Wistar (WIS) rats were also used to investigate whether the putative effects of environmental enrichment depend on a specific genetic background. The animals were reared in enriched environment (EE) or standard environment (SE) from the post-natal day 21 until 3 months of age (adulthood) and tested for cognitive and non-cognitive phenotypes. EE improved SHR's performance in open field habituation, water maze spatial reference, social and object recognition tasks, while non-cognitive traits, such as nociception and hypertension, were not affected by EE. Response of WIS rats was generally not affected by the present EE. These results show that the general low cognitive performance presented by SHR rats strongly depends on the rearing environment and they may suggest modifications of the familial environment as a putative preventive strategy to cope with ADHD.