The neural basis of deficits in acquisition and extinction of fear in schizophren

描述（由申请人提供）：精神分裂症患者表现出情感学习和记忆方面的缺陷，这与该疾病的症状有关。然而，这些缺陷的神经生物学基础尚不清楚。与这个问题相关的一个具有挑战性的问题是，用于治疗精神分裂症的药物也会导致情绪功能的一些损害，因此在以前的研究中，很难将这种疾病的影响与大多数患者使用的药物的影响区分开来。一种用于研究哺乳动物（包括人类）情绪学习和记忆的常用方法被称为巴甫洛夫恐惧条件反射。在巴甫洛夫恐惧条件反射程序中，一个人暴露于中性刺激，如音调或图片，然后是不愉快的感觉，如大声噪音或轻微的电刺激。在重复一定次数的这个过程之后，当暴露于中性刺激本身时，人开始经历一些预期的焦虑或恐惧。第二种类型的学习可以发生在这种中性刺激之后被多次呈现而没有随后出现不愉快的刺激时;这被称为消退学习，它需要形成与恐惧记忆分开编码的记忆痕迹。这些恐惧和消失的记忆可以在稍后的时间被回忆起来，这取决于记忆形成和回忆过程中的环境（称为“背景”）。我们已经发现证据表明，学习和后来的回忆恐惧和灭绝的记忆是不正常的精神分裂症。在这个项目中，我们将测试这样一个假设，即精神分裂症中恐惧和灭绝学习和记忆的这些异常与已知驱动这些过程的大脑区域功能的特定变化有关，并且这些神经变化与精神分裂症的特定症状有关。我们还将确定该系统中的任何异常是否是由抗精神病药物治疗引起的，是否会恶化或改善。该项目对理解精神分裂症的基本病理生理学以及开发该疾病的早期标记物和新治疗方法具有意义。

DESCRIPTION (provided by applicant): People who develop schizophrenia show deficits in emotional learning and memory, which have been linked to the symptoms of the disorder. Yet the neurobiological basis of these deficits is unknown. One challenging issue associated with this question is that the medications used to treat schizophrenia also cause some impairment in emotional function, so it has been difficult in previous studies to distinguish effects of the disorder from those of the medications used by the majority of the patients with the illness. One common method used to study emotional learning and memory in mammals, including humans, is called Pavlovian fear conditioning. In Pavlovian fear conditioning procedures, a person is exposed to a neutral stimulus, such as a tone or picture, which is followed by an unpleasant sensation, such as a loud noise or mild electrical stimulus. After a certain number of repetitions of this procedure, the person begins to experience some anticipatory anxiety or fear when exposed to the neutral stimulus by itself. A second type of learning can occur when this neutral stimulus is later presented several times without being followed by the unpleasant stimulus; this is called extinction learning and it requires the formation of a memory trace that is coded separately from the fear memory. These fear and extinction memories can be recalled at a later time, depending on the circumstances (called the "context") during the formation and recall of the memories. We have found evidence suggesting that the learning and later recall of fear and extinction memories is abnormal in schizophrenia. In this project, we will test the hypothesis that these abnormalities in fear and extinction learning and memory in schizophrenia are related to specific changes in the function of the brain regions known to drive these processes, and that these neural changes are linked to specific symptoms of schizophrenia. We will also determine whether any of the abnormalities in this system arise from, are worsened or improved by treatment with antipsychotic medications. This project has implications for understanding the fundamental pathophysiology of schizophrenia and for developing early markers and new treatments for the disorder.