Effects of metamfetamine on auditory P3 component of event-related potentials in rats

Three rats were trained with an oddball paradigm, in which 5 kHz frequent and 10 kHz target rare tones were presented with a probability of 0.8 and 0.2. Pressing the lever within 2 s following the onset of the target tones was rewarded with a drop of food paste. Long latency event-related potentials (ERPs) corresponding to those in humans could be recorded in rats. After the administration of metamfetamine (0.2 mg/kg), the amplitude of surface and intracortical N1 increased, indicating an augmentation of the primary cortical response. Surface P3 showed a decrease of amplitude, accompanied by an increase of intracortical negativity. These alterations of ERPs may be caused by the dysregulation of central noradrenergic system.