Department of Integrative Neurophysiology, Chiba University Graduate School of Medicine, 1-8-1 Inohana, Chiba 260-8670, Japan.
Prog Neuropsychopharmacol Biol Psychiatry. 2010 Feb 1;34(1):183-8. doi: 10.1016/j.pnpbp.2009.10.023. Epub 2009 Nov 14.
Prepulse inhibition (PPI) of the acoustic startle response is one of the few and major paradigms for investigating sensorimotor gating systems in humans and rodents in a similar fashion. PPI deficits are observed not only in patients with schizophrenia, but also in patients with anxiety disorders. Previous studies have shown that PPI in rats can be enhanced by auditory fear conditioning. In this study, we evaluated the effects of contextual fear conditioning (FC) for six times a day and fear extinction (FE) for seven days on PPI in mice. C57BL/6J mice (male, 8-12 weeks) were divided into three groups; no-FC (control), FC and FC + FE. We measured PPI at the following three time points, (1) baseline before FC, (2) after FC, and (3) after FE. The results showed that PPI was increased after FC. Moreover, the enhanced PPI following FC was observed even after FE with decreased freezing behaviors. These results suggested contextual fear conditioning could enhance acoustic PPI, and that contextual fear extinction could decrease freezing behaviors, but not acoustic PPI.
预备性惊吓反应的前脉冲抑制（PPI）是一种为数不多但主要的范式，可以在人类和啮齿动物中以类似的方式研究感觉运动门控系统。不仅在精神分裂症患者中观察到 PPI 缺陷，而且在焦虑症患者中也观察到 PPI 缺陷。先前的研究表明，大鼠的 PPI 可以通过听觉恐惧条件反射得到增强。在这项研究中，我们评估了每天进行六次的情境恐惧条件反射（FC）和七天的恐惧消退（FE）对小鼠 PPI 的影响。C57BL/6J 小鼠（雄性，8-12 周）分为三组；无 FC（对照组）、FC 和 FC+FE。我们在以下三个时间点测量 PPI：（1）FC 前的基线，（2）FC 后，（3）FE 后。结果表明，FC 后 PPI 增加。此外，即使在冷冻行为减少的情况下，在 FC 后仍观察到增强的 PPI。这些结果表明，情境恐惧条件反射可以增强听觉 PPI，而情境恐惧消退可以降低冷冻行为，但不能增强听觉 PPI。
