1. Evaluation of light/dark cycle in anxiety- and depressive-like behaviors after regular treatment with methylphenidate hydrochloride in rats of different ages.
- Author
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Gomes KM, Souza RP, Inácio CG, Valvassori SS, Réus GZ, Martins MR, Comim CM, and Quevedo J
- Subjects
- Age Factors, Animals, Anxiety Disorders psychology, Attention Deficit Disorder with Hyperactivity drug therapy, Depressive Disorder psychology, Male, Rats, Rats, Wistar, Anti-Anxiety Agents therapeutic use, Antidepressive Agents therapeutic use, Anxiety Disorders drug therapy, Depressive Disorder drug therapy, Methylphenidate therapeutic use, Photoperiod
- Abstract
Objective: Methylphenidate hydrochloride is the most widely used medication for treatment and management of attention-deficit hyperactivity disorder. However, the chronic effects of methylphenidate hydrochloride on anxiety- and depressive-like rat behaviors remain poorly investigated. In this context, the present study evaluated the effects of treatment with methylphenidate hydrochloride on anxiety- and depressive-like behaviors using young and adult rats during the light and the dark cycle., Method: Male Wistar rats (25 or 60 days old) received a once-daily (in either the light or dark cycle) methylphenidate hydrochloride (2mg/kg) or saline intraperitoneal injection for 28 days. We performed elevated plus maze and forced swimming test two hours after the last injection., Results: The light/dark cycle was a significant factor in the anxiety-like behaviors; however, no significant interaction between all three factors (cycle, age and methylphenidate hydrochloride) was found. Nevertheless, we observed a nominally significant interaction between the light/ dark cycle and age in the forced swimming test., Conclusion: Our results have shown that age and the light/dark cycle are more significant modulators of anxiety- and depressive-like behaviors than methylphenidate hydrochloride treatment.
- Published
- 2011
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