Lurasidone (SM-13496), a novel atypical antipsychotic drug, reverses MK-801-induced impairment of learning and memory in the rat passive-avoidance test

Eur J Pharmacol. 2007 Oct 31;572(2-3):160-70. doi: 10.1016/j.ejphar.2007.06.058. Epub 2007 Jul 10.

Abstract

Lurasidone (SM-13496) is a novel atypical antipsychotic with high affinities to dopamine D2, serotonin 5-HT7, 5-HT2A, 5-HT1A receptors and alpha2C adrenoceptor. In this study, the effects of lurasidone on the rat passive-avoidance response and its impairment by the N-methyl-D-aspartate (NMDA) receptor antagonist MK-801 (dizocilpine) were evaluated and compared with those of other antipsychotics. The passive-avoidance response was examined by measuring the step-through latency, 1 day after the animals received foot-shock training. When given before the training session, lurasidone did not affect the passive-avoidance response at any dose tested (1-30 mg/kg, p.o.). All the other atypical antipsychotics examined (i.e., risperidone, olanzapine, quetiapine, clozapine and aripiprazole), however, significantly reduced the step-through latency at relatively high doses. A pre-training administration of lurasidone significantly and dose-dependently reversed the MK-801-induced impairment of the passive-avoidance response. At doses lower than those that affected the passive-avoidance response, risperidone, quetiapine, and clozapine partially reduced the MK-801-induced impairment, whereas haloperidol, olanzapine, and aripiprazole were inactive. In addition, the post-training administration of lurasidone was as effective in countering the MK-801 effect as the pre-training administration, suggesting that lurasidone worked, at least in part, by restoring the memory consolidation process disrupted by MK-801. These results suggest that lurasidone is superior to other antipsychotics in improving the MK-801-induced memory impairment and may be clinically useful for treating cognitive impairments in schizophrenia.

MeSH terms

  • Animals
  • Antipsychotic Agents / pharmacology*
  • Avoidance Learning / drug effects*
  • Dizocilpine Maleate / toxicity*
  • Dopamine D2 Receptor Antagonists*
  • Isoindoles / pharmacology*
  • Lurasidone Hydrochloride
  • Male
  • Memory / drug effects*
  • Rats
  • Rats, Wistar
  • Reaction Time / drug effects
  • Serotonin 5-HT2 Receptor Antagonists*
  • Thiazoles / pharmacology*

Substances

  • Antipsychotic Agents
  • Dopamine D2 Receptor Antagonists
  • Isoindoles
  • Serotonin 5-HT2 Receptor Antagonists
  • Thiazoles
  • Dizocilpine Maleate
  • Lurasidone Hydrochloride