Phencyclidine (PCP): effects on auditory evoked potentials in the rhesus monkey

Area of Science:

• Neuroscience
• Pharmacology
• Auditory System Research

Background:

• Phencyclidine (PCP) is a dissociative drug with known central nervous system effects.
• Auditory evoked potentials (AEPs) are electrophysiological measures reflecting auditory pathway function.

Purpose of the Study:

• To investigate the acute and chronic effects of phencyclidine (PCP) on auditory evoked potentials (AEPs) in rhesus monkeys.
• To identify specific central nervous system structures affected by PCP administration.

Main Methods:

• Rhesus monkeys with implanted encephalic electrodes were used.
• Auditory evoked potentials were recorded following single click stimuli.
• Acute and chronic administration of phencyclidine (PCP) at specified doses (2.0 or 4.0 mg/kg IV) was performed.

Main Results:

• Acute PCP administration caused significant amplitude distortions in AEP components within the superior temporal cortex (ST) and medial geniculate body (MGB).
• These acute effects persisted for 4 to 5 hours.
• Chronic PCP administration (4.0 mg/kg IV daily) enhanced AEP distortions in the ST but showed minimal additional effects in the MGB.

Conclusions:

• PCP disrupts AEPs in key auditory processing centers (ST and MGB) in rhesus monkeys.
• Chronic PCP exposure potentiates AEP alterations in the primary auditory cortex (ST) more than in subcortical pathways (MGB).