Posterior Parietal Cortex Persistent Activity and Working Memory

人类能够在短时间内同时存储的东西（我们的工作记忆）非常少。最大值被认为是7，就像电话号码中的数字一样，但平均值只有4！我们工作记忆的有限容量取决于分布在我们大脑额叶和顶叶的神经机制，但我们目前的知识状态还远未完成。一方面，由于没有足够的动物模型来研究工作记忆容量，因此只研究了基本的记忆机制。另一方面，尽管所有的证据都表明顶叶皮层也起着重要作用，但我们对这些基本记忆机制的了解几乎都是从对额叶皮层的研究中获得的。** 在该基金的最后一个任期内，我们建立了一个新的动物模型来研究工作记忆，方法是采用一个简单的程序，该程序已被广泛用于人类。在这个提议中，我们将研究顶叶皮层内的工作记忆的大多数未被探索的神经基质。当动物执行我们新的工作记忆任务时，我们将使用微电极从单个神经元和小神经元集合中识别工作记忆的神经特征，并使用脑电图从大规模神经元群体中识别工作记忆的神经特征。此外，我们将通过测试药物对行为任务和神经活动的影响来确定特定神经递质受体对工作记忆的贡献。** 这项研究的结果将对大脑皮层神经元内和神经元之间发生的信息处理的基础研究产生影响，这可以应用于其他大脑功能，即，我们感知和注意力的极限。此外，它将允许具有不同背景的学生-如生物学，心理学，工程学，计算机和认知科学-在几种实验方法中获得高质量的培训。这种研究经验将使他们准备进入研究的各个领域作为新兴的年轻领导者，从而有助于满足学术界和行业对高素质人才日益增长的需求。

The number of things that humans can hold simultaneously in memory for a short time (our working memory) is remarkably small. The maximum is thought to be seven, as in the number of digits in a phone number, but the average is about only four! The limited capacity of our working memory depends on neural mechanisms that are distributed in the frontal and parietal lobes of our brain, but the current state of our knowledge is far from complete. On the one hand, only basic memory mechanisms have been studied because there exists no adequate animal model to study working memory capacity. On the other hand, nearly all our knowledge about these basic memory mechanisms has been obtained from studies of the frontal cortex despite all the evidence indicating that the parietal cortex also plays an important role. ******In the last tenure of this grant, we have established a new animal model to study working memory by adapting a simple procedure that has been extensively used in humans for that purpose. In this proposal, we will study the mostly unexplored neural substrate of working memory within the parietal cortex. While animals perform our novel working memory task, we will identify the neural signature of working memory from single neurons and small ensembles of neurons using microelectrodes and from large-scale populations of neurons using encephalography. In addition, we will determine the contribution of specific neurotransmitter receptors to working memory by testing the effects of drugs on performance in the behavioral task and on neural activity. ******The results of this research will have implications for the basic study of information processing taking place within and between neurons of the cerebral cortex, which can be applied to other brain functions, i.e., the limits of our perception and attention. In addition, it will allow students with diverse background - such as biology, psychology, engineering, computer and cognitive science - to gain high quality training in several experimental methods. This research experience will prepare them to enter various areas of research as emerging young leaders, thereby helping to satisfy the increasing demand for highly qualified individuals in academia and industries.**