Clozapine Reverses Phencyclidine-Induced Desynchronization of Prefrontal Cortex through a 5-HT(1A) Receptor-Dependent Mechanism

Neuropsychopharmacology. 2012 Feb;37(3):723-33. doi: 10.1038/npp.2011.249. Epub 2011 Oct 19.


The non-competitive NMDA receptor (NMDA-R) antagonist phencyclidine (PCP)-used as a pharmacological model of schizophrenia-disrupts prefrontal cortex (PFC) activity. PCP markedly increased the discharge rate of pyramidal neurons and reduced slow cortical oscillations (SCO; 0.15-4 Hz) in rat PFC. Both effects were reversed by classical (haloperidol) and atypical (clozapine) antipsychotic drugs. Here we extended these observations to mice brain and examined the potential involvement of 5-HT(2A) and 5-HT(1A) receptors (5-HT(2A)R and 5-HT(1A)R, respectively) in the reversal by clozapine of PCP actions. Clozapine shows high in vitro affinity for 5-HT(2A)R and behaves as partial agonist in vivo at 5-HT(1A)R. We used wild-type (WT) mice and 5-HT(1A)R and 5-HT(2A)R knockout mice of the same background (C57BL/6) (KO-1A and KO-2A, respectively). Local field potentials (LFPs) were recorded in the PFC of WT, KO-1A, and KO-2A mice. PCP (10 mg/kg, intraperitoneally) reduced SCO equally in WT, KO-2A, and KO-1A mice (58±4%, 42±7%, and 63±7% of pre-drug values, n=23, 13, 11, respectively; p<0.0003). Clozapine (0.5 mg/kg, intraperitoneally) significantly reversed PCP effect in WT and KO-2A mice, but not in KO-1A mice nor in WT mice pretreated with the selective 5-HT(1A)R antagonist WAY-100635.The PCP-induced disorganization of PFC activity does not appear to depend on serotonergic function. However, the lack of effect of clozapine in KO-1A mice and the prevention by WAY-100635 indicates that its therapeutic action involves 5-HT(1A)R activation without the need to block 5-HT(2A)R, as observed with clozapine-induced cortical dopamine release.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Clozapine / pharmacology*
  • Excitatory Amino Acid Antagonists / pharmacology*
  • Mice
  • Mice, Knockout
  • Neurons / drug effects
  • Neurons / physiology
  • Phencyclidine / pharmacology*
  • Piperazines / pharmacology
  • Prefrontal Cortex / drug effects*
  • Prefrontal Cortex / metabolism
  • Pyridines / pharmacology
  • Receptor, Serotonin, 5-HT1A / metabolism*
  • Receptor, Serotonin, 5-HT2A / metabolism
  • Serotonin Antagonists / pharmacology*


  • Excitatory Amino Acid Antagonists
  • Piperazines
  • Pyridines
  • Receptor, Serotonin, 5-HT2A
  • Serotonin Antagonists
  • Receptor, Serotonin, 5-HT1A
  • N-(2-(4-(2-methoxyphenyl)-1-piperazinyl)ethyl)-N-(2-pyridinyl)cyclohexanecarboxamide
  • Phencyclidine
  • Clozapine