Synaptic theory of working memory.
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.
Mongillo
Gianluigi
G
Group for Neural Theory, Département d'Etudes Cognitives, Ecole Normale Supérieure et Collège-de-France, Paris, France.
Barak
Omri
O
Tsodyks
Misha
M
D000200:Action Potentials; D002118:Calcium / Q000378:metabolism*; D006801:Humans; D008433:Mathematics; D008568:Memory / Q000502:physiology*; D008959:Models, Neurological; D009415:Nerve Net / Q000502:physiology; D009434:Neural Pathways; D009473:Neuronal Plasticity; D009474:Neurons / Q000502:physiology; D018377:Neurotransmitter Agents / Q000378:metabolism; D017397:Prefrontal Cortex / Q000502:physiology*; D017729:Presynaptic Terminals / Q000502:physiology; D013569:Synapses / Q000502:physiology*; D009435:Synaptic Transmission
D018377:Neurotransmitter Agents; D002118:Calcium