dendritic hold and read a gated mechanism for short term information storage and retrieval树突和阅读一封闭的短期信息存储和检索机制.pdfVIP

Dendritic Hold and Read: A Gated Mechanism for Short Term Information Storage and Retrieval 1. 1. 1 1 2 Mariton D. Santos , Michael H. Mohammadi , Sunggu Yang , Conrad W. Liang , Joseph P. Y. Kao , 2 2 1,2,3 Bradley E. Alger , Scott M. Thompson , Cha-Min Tang * 1 Departments of Neurology, University of Maryland School of Medicine, Baltimore, Maryland, United States of America, 2 Department of Physiology, University of Maryland School of Medicine, Baltimore, Maryland, United States of America, 3 Baltimore Veterans Administration Medical Center, Baltimore, Maryland, United States of America Abstract Two contrasting theories have been proposed to explain the mechanistic basis of short term memory. One theory posits that short term memory is represented by persistent neural activity supported by reverberating feedback networks. An alternate, more recent theory posits that short term memory can be supported by feedforward networks. While feedback driven memory can be implemented by well described mechanisms of synaptic plasticity, little is known of possible molecular and cellular mechanisms that can implement feedforward driven memory. Here we report such a mechanism in which the memory trace exists in the form of glutamate-bound but Mg2+-blocked NMDA receptors on the thin terminal dendrites of CA1 pyramidal neurons. Because glutamate dissociates from subsets of NMDA receptors very slowly, excitatory synaptic transmission can leave a silent residual trace that outlasts the electrical activity by hundreds of milliseconds. Read- out of the memory tr