Modulation of mGlu2 Receptors, but Not PDE10A Inhibition Normalizes Pharmacologically-Induced Deviance in Auditory Evoked Potentials and Oscillations in Conscious Rats

PLoS One. 2016 Jan 25;11(1):e0147365. doi: 10.1371/journal.pone.0147365. eCollection 2016.

Abstract

Improvement of cognitive impairments represents a high medical need in the development of new antipsychotics. Aberrant EEG gamma oscillations and reductions in the P1/N1 complex peak amplitude of the auditory evoked potential (AEP) are neurophysiological biomarkers for schizophrenia that indicate disruption in sensory information processing. Inhibition of phosphodiesterase (i.e. PDE10A) and activation of metabotropic glutamate receptor (mGluR2) signaling are believed to provide antipsychotic efficacy in schizophrenia, but it is unclear whether this occurs with cognition-enhancing potential. The present study used the auditory paired click paradigm in passive awake Sprague Dawley rats to 1) model disruption of AEP waveforms and oscillations as observed in schizophrenia by peripheral administration of amphetamine and the N-methyl-D-aspartate (NMDA) antagonist phencyclidine (PCP); 2) confirm the potential of the antipsychotics risperidone and olanzapine to attenuate these disruptions; 3) evaluate the potential of mGluR2 agonist LY404039 and PDE10 inhibitor PQ-10 to improve AEP deficits in both the amphetamine and PCP models. PCP and amphetamine disrupted auditory information processing to the first click, associated with suppression of the P1/N1 complex peak amplitude, and increased cortical gamma oscillations. Risperidone and olanzapine normalized PCP and amphetamine-induced abnormalities in AEP waveforms and aberrant gamma/alpha oscillations, respectively. LY404039 increased P1/N1 complex peak amplitudes and potently attenuated the disruptive effects of both PCP and amphetamine on AEPs amplitudes and oscillations. However, PQ-10 failed to show such effect in either models. These outcomes indicate that modulation of the mGluR2 results in effective restoration of abnormalities in AEP components in two widely used animal models of psychosis, whereas PDE10A inhibition does not.

MeSH terms

  • Animals
  • Antipsychotic Agents / pharmacology
  • Benzodiazepines / pharmacology
  • Bridged Bicyclo Compounds, Heterocyclic / pharmacology
  • Consciousness / drug effects
  • Cyclic S-Oxides / pharmacology
  • Evoked Potentials, Auditory / drug effects*
  • Male
  • Olanzapine
  • Phosphoric Diester Hydrolases / metabolism*
  • Rats
  • Rats, Sprague-Dawley
  • Receptors, Metabotropic Glutamate / agonists
  • Receptors, Metabotropic Glutamate / metabolism*
  • Risperidone / pharmacology

Substances

  • 4-aminho-2-thiabicyclo(3.1.0)hexane-4,6-dicarboxylic acid
  • Antipsychotic Agents
  • Bridged Bicyclo Compounds, Heterocyclic
  • Cyclic S-Oxides
  • Receptors, Metabotropic Glutamate
  • Benzodiazepines
  • PDE10A protein, rat
  • Phosphoric Diester Hydrolases
  • Risperidone
  • Olanzapine

Grants and funding

The authors received no specific funding for this work. All authors are employed by Janssen Research & Development. Janssen Research & Development provided support in the form of salaries for authors [AA, RB and WD], but did not have any additional role in the study design, data collection and analysis, decision to publish, or preparation of the manuscript. The specific roles of these authors are articulated in the 'author contributions' section.