Stably maintained dendritic spines are associated with lifelong memories.
Changes in synaptic connections are considered essential for learning and memory formation. However, it is unknown how neural circuits undergo continuous synaptic changes during learning while maintaining lifelong memories. Here we show, by following postsynaptic dendritic spines over time in the mouse cortex, that learning and novel sensory experience lead to spine formation and elimination by a protracted process. The extent of spine remodelling correlates with behavioural improvement after learning, suggesting a crucial role of synaptic structural plasticity in memory formation. Importantly, a small fraction of new spines induced by novel experience, together with most spines formed early during development and surviving experience-dependent elimination, are preserved and provide a structural basis for memory retention throughout the entire life of an animal. These studies indicate that learning and daily sensory experience leave minute but permanent marks on cortical connections and suggest that lifelong memories are stored in largely stably connected synaptic networks.
Yang
Guang
G
Molecular Neurobiology Program, The Helen and Martin Kimmel Center for Biology and Medicine at the Skirball Institute of Biomolecular Medicine, Department of Physiology and Neuroscience, New York University School of Medicine, New York, New York 10016, USA.
Pan
Feng
F
Gan
Wen-Biao
WB
D000375:Aging / Q000502:physiology; D000818:Animals; D049229:Dendritic Spines / Q000378:metabolism / Q000502:physiology*; D005552:Forelimb / Q000502:physiology; D008568:Memory / Q000502:physiology*; D051379:Mice; D009044:Motor Cortex / Q000166:cytology / Q000502:physiology; D009048:Motor Skills / Q000502:physiology; D009473:Neuronal Plasticity / Q000502:physiology; D017966:Pyramidal Cells / Q000378:metabolism; D013569:Synapses / Q000378:metabolism*; D013997:Time Factors