Effects of neurotensin-2 receptor deletion on sensorimotor gating and locomotor activity.

Endogenous neurotensin (NT) has been implicated in brain processes relevant to schizophrenia as well as the therapeutic effects of antipsychotic drugs (APDs) used to treat this disorder. Converging evidence suggests that NT1 receptors mediate the antipsychotic-like effects of NT, such as prepulse inhibition (PPI) elevation. However, the role of NT2 receptors in these effects is not known. To investigate the contribution of NT2 receptors to the regulation of PPI, we measured baseline PPI and acoustic startle response (ASR), in male and female wild type (WT) and NT2 knockout (KO) mice. For comparison, we also measured locomotor activity. Baseline PPI was significantly elevated in both male (P<0.01) and female (P<0.01) NT2 KO compared to WT mice, while ASR was significantly decreased in KO mice of both genders (P<0.01). In contrast, female but not male KO mice exhibited significantly less baseline ambulations (P<0.05). These data support the regulation of baseline PPI, ASR and locomotor activity by endogenous NT acting at the NT2 receptor. Further studies investigating the role of NT2 receptors in the modulation of APD-like effects are warranted.