Mongillo Gianluigi, Barak Omri, Tsodyks Misha
Group for Neural Theory, Département d'Etudes Cognitives, Ecole Normale Supérieure et Collège-de-France, Paris, France.
Science. 2008 Mar 14;319(5869):1543-6. doi: 10.1126/science.1150769.
It is usually assumed that enhanced spiking activity in the form of persistent reverberation for several seconds is the neural correlate of working memory. Here, we propose that working memory is sustained by calcium-mediated synaptic facilitation in the recurrent connections of neocortical networks. In this account, the presynaptic residual calcium is used as a buffer that is loaded, refreshed, and read out by spiking activity. Because of the long time constants of calcium kinetics, the refresh rate can be low, resulting in a mechanism that is metabolically efficient and robust. The duration and stability of working memory can be regulated by modulating the spontaneous activity in the network.
通常认为,以持续数秒的回响形式增强的尖峰活动是工作记忆的神经关联。在此,我们提出工作记忆由新皮层网络递归连接中钙介导的突触易化来维持。在这种观点中,突触前残余钙用作一种缓冲器,通过尖峰活动进行加载、更新和读取。由于钙动力学的时间常数较长,更新速率可以较低,从而产生一种代谢高效且稳健的机制。工作记忆的持续时间和稳定性可通过调节网络中的自发活动来调控。