Behavioral reactivity to a noradrenergic challenge after chronic oral methylphenidate (ritalin) in rats.

摘要: Methylphenidate (Ritalin®) is routinely used for the treatment of attention-deficit/hyperactivity disorder (ADHD). It a psychomotor stimulant with pharmacodynamics similar to those established cocaine and amphetamine primary activation noradrenergic dopaminergic systems. Long-term exposure psychostimulants including methylphenidate (MPD) believed result in enduring functional changes along both these pathways various behaviors mediated by systems may be affected. In present experiment, effects intermittent oral administration (10 mg/kg) rats over 4-week period were subsequently (after drug washout interval) assessed three animal models sensitive manipulation: elevated plus-maze, predator odor avoidance, social interaction tests. The methylphenidate-experienced animals compared untreated controls. Thirty minutes prior testing, half each histories received an injection yohimbine hydrochloride (2.0 mg/kg), α2-adrenoreceptor blocker intended evoke system activation, while remainder saline injection. Yohimbine was expected reduce exploration novel stimuli conspecifics, it predicted that would potentiate effects. Relative saline-tested controls, challenge exhibited least test lowest duration unfamiliar conspecific partner test. behavior patterns observed this group suggest heightened emotionality defensiveness are typically seen when administered drugs known anxiogenic human subjects. exploratory locomotor activities remained unaltered either decreased risk-assessment behaviors, effect uninfluenced pretreatment.