Extensive enriched environments protect old rats from the aging dependent impairment of spatial cognition, synaptic plasticity and nitric oxide production

• Published in: Behavioural brain research Vol. 169; no. 2; pp. 294 - 302
• Main Authors: Lores-Arnaiz, S., Bustamante, J., Arismendi, M., Vilas, S., Paglia, N., Basso, N., Capani, F., Coirini, H., Costa, J.J. López, Arnaiz, M.R. Lores
• Format: Journal Article
• Language: English
• Published: Shannon Elsevier B.V 15.05.2006; Elsevier Science
• Subjects: Aged rats; Aging; Analysis of Variance; Animals; Biological and medical sciences; Blotting, Western - methods; Brain - cytology; Brain - metabolism; Brain plasticity; Cell Count - methods; Cognition Disorders - prevention & control; Cognition. Intelligence; Diagnostic Imaging; Enriched environments; Environment; Female; Fundamental and applied biological sciences. Psychology; Immunohistochemistry - methods; Luminescent Measurements - methods; Male; Maze Learning - physiology; Memory, Short-Term - physiology; Miscellaneous; Mitochondria - metabolism; Mitochondrial respiratory complexes; NADP - metabolism; Neuronal Plasticity - physiology; Nitric Oxide - metabolism; Nitric oxide synthase; Nitric Oxide Synthase Type I - metabolism; Psychology. Psychoanalysis. Psychiatry; Psychology. Psychophysiology; Rats; Rats, Sprague-Dawley; Spatial Behavior - physiology; Time Factors; Working memory; Nitric oxide synthase; Brain plasticity; Aged rats; Enriched environments; Working memory; Mitochondrial respiratory complexes; Working memory: Brain plasticity: Nitric oxide synthase; Senescence; Rat; Rodentia; Environmental factor; Cognition; Stimulating environment; Medium enrichment; Vertebrata; Mammalia; Animal; Nitric oxide; Synaptic plasticity; Mitochondrial respiratory complexes: Aged rats
• ISSN: 0166-4328; 1872-7549
• DOI: 10.1016/j.bbr.2006.01.016

In aged rodents, neuronal plasticity decreases while spatial learning and working memory (WM) deficits increase. As it is well known, rats reared in enriched environments (EE) show better cognitive performances and an increased neuronal plasticity than rats reared in standard environments (SE). We hypothesized that EE could preserve the aged animals from cognitive impairment through NO dependent mechanisms of neuronal plasticity. WM performance and plasticity were measured in 27-month-old rats from EE and SE. EE animals showed a better spatial WM performance (66% increase) than SE ones. Cytosolic NOS activity was 128 and 155% higher in EE male and female rats, respectively. Mitochondrial NOS activity and expression were also significantly higher in EE male and female rats. Mitochondrial NOS protein expression was higher in brain submitochondrial membranes from EE reared rats. Complex I activity was 70–80% increased in EE as compared to SE rats. A significant increase in the area of NADPH-d reactive neurons was observed in the parietotemporal cortex and CA1 hippocampal region of EE animals.