Quirk M C, Blum K I, Wilson M A
The Department of Brain and Cognitive Sciences, Center for Learning and Memory, and the RIKEN-Massachusetts Institute of Technology Neuroscience Research Center, The Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.
J Neurosci. 2001 Jan 1;21(1):240-8. doi: 10.1523/JNEUROSCI.21-01-00240.2001.
Activity-dependent attenuations in extracellular spike amplitude have been shown to correlate with a decrease in the effectiveness with which somatic action potentials back-propagate into the dendritic arbor of hippocampal pyramidal cells. In this paper we demonstrate that activity-dependent attenuations in amplitude occur during behavior and that the amount of attenuation is reduced with an animal's experience in an environment. The observed reductions are caused by an animal's experience within a specific environmental context, are dependent on functional NMDA receptors, and are accompanied by an increase in the effective coupling of pyramidal cells and interneurons. These results provide an important step in linking together in vivo studies with in vitro data and suggest that mechanisms of plasticity engaged during behavior may be sufficient to alter the biophysical and integrative properties of hippocampal pyramidal cells.
细胞外锋电位幅度的活动依赖性衰减已被证明与体细胞动作电位反向传播到海马锥体细胞树突分支的有效性降低相关。在本文中，我们证明了幅度的活动依赖性衰减在行为过程中发生，并且衰减量会随着动物在环境中的经验而减少。观察到的衰减减少是由动物在特定环境背景下的经验引起的，依赖于功能性NMDA受体，并且伴随着锥体细胞和中间神经元有效耦合的增加。这些结果为将体内研究与体外数据联系起来迈出了重要一步，并表明行为过程中参与的可塑性机制可能足以改变海马锥体细胞的生物物理和整合特性。
