Long-Term Effects of Chronic Oral Ritalin Administration on Cognitive and Neural Development in Adolescent Wistar Kyoto Rats

Brain Sciences

Margery C. Pardey¹  Natasha N. Kumar²  Ann K. Goodchild²  Kelly J. Clemens¹  Judi Homewood¹ 

[1] Department of Psychology, Macquarie University, Sydney 2109, Australia;The Australian School of Advanced Medicine, Macquarie University, Sydney 2109, Australia;

关键词: methylphenidate;    adolescent;    tyrosine hydroxylase;    chronic administration;    prefrontal cortex;    impulsivity;    impulsive choice;   

DOI  :  10.3390/brainsci2030375

来源: mdpi

【 摘 要 】

The diagnosis of Attention Deficit Hyperactivity Disorder (ADHD) often results in chronic treatment with psychostimulants such as methylphenidate (MPH, Ritalin^®). With increases in misdiagnosis of ADHD, children may be inappropriately exposed to chronic psychostimulant treatment during development. The aim of this study was to assess the effect of chronic Ritalin treatment on cognitive and neural development in misdiagnosed “normal” (Wistar Kyoto, WKY) rats and in Spontaneously Hypertensive Rats (SHR), a model of ADHD. Adolescent male animals were treated for four weeks with oral Ritalin^® (2 × 2 mg/kg/day) or distilled water (dH₂O). The effect of chronic treatment on delayed reinforcement tasks (DRT) and tyrosine hydroxylase immunoreactivity (TH-ir) in the prefrontal cortex was assessed. Two weeks following chronic treatment, WKY rats previously exposed to MPH chose the delayed reinforcer significantly less than the dH₂O treated controls in both the DRT and extinction task. MPH treatment did not significantly alter cognitive performance in the SHR. TH-ir in the infralimbic cortex was significantly altered by age and behavioural experience in WKY and SHR, however this effect was not evident in WKY rats treated with MPH. These results suggest that chronic treatment with MPH throughout adolescence in “normal” WKY rats increased impulsive choice and altered catecholamine development when compared to vehicle controls.

【 授权许可】

CC BY   
© 2012 by the authors; licensee MDPI, Basel, Switzerland.