The effects of reboxetine with modafinil on noxious tail pinch-induced sensorimotor gating reactivity in rats

Background: Prepulse inhibition (PPI) is an indicator of sensorimotor gating reactivity in rodents and humans sensitive to psychotropic drugs. Studies suggest increased or decreased dopamine levels in the brain alter several modalities of sensorimotor gating. However, so far, little is known about the role norepinephrine (NE) plays on such mechanisms. An antidepressant agent, reboxetine (RBX), is a selective NE transporter blockade that can affect PPI in patients with major depression by elevating synaptic NE levels. Methods: The present study was designed to examine the effects of RBX versus the wake-promoting agent, modafinil (MOD), on the PPI of tail-pinch (TP) challenged rats. Results: The results showed a disparity in changes of sensorimotor gating reactivity between RBX and MOD administrations in rats during noxious TP stress. Conclusion: These data indicated the antidepressant mechanisms of RBX and MOD might differ. We do not support the view that MOD is promising as an augmenter of antidepressants.