The DBA/2J strain and prepulse inhibition of startle: a model system to test antipsychotics?

Abstract.

Rationale: Prepulse inhibition (PPI) of the startle response in mice is increasingly used as a paradigm of sensory gating with potential predictive and construct validity towards schizophrenia. Objectives: Establishment of a mouse PPI paradigm in which typical and atypical antipsychotic drugs directly improve a low performance PPI. Methods: Three strains of mice – C57Bl/6J, 129S6/SvEvTac and DBA/2J – were tested in a startle paradigm with three prepulse intensities, 2, 4 and 8 dB above background. Results: Under these conditions, risperidone (0, 0.25, 0.5 and 1 mg/kg i.p.) and clozapine (0, 1, 3 and 9 mg/kg i.p.) improved PPI in all three strains, with order of effect in DBA/2J > 129S6SvEvTac > C57Bl/6J. The DBA/2J strain showed larger PPI-enhancing effects, without disturbing the basal startle response. Two α₇ nicotinic receptor agonists, GTS-21 (1–10 mg/kg i.p.) and AR-R17779 (1–10 mg/kg i.p.) were inactive in the PPI procedure in DBA/2J mice. Conclusions: DBA/2J mice were very sensitive to the antipsychotic-like effects of atypical (clozapine) and typical (risperidone) antipsychotics, and this strain is proposed as a model to directly measure sensory gating properties of drugs. α₇ Nicotinergic receptor agonists were ineffective in this PPI paradigm.