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Author Chen, Shanping ♦ Cai, Diancai ♦ Pearce, Kaycey ♦ Sun, Philip Y-W ♦ Roberts, Adam C. ♦ Glanzman, David L.
Source Paperity
Content type Text
Publisher eLife Sciences Publications, Ltd
File Format PDF ♦ HTM / HTML
Copyright Year ©2014
Abstract Long-term memory (LTM) is believed to be stored in the brain as changes in synaptic connections. Here, we show that LTM storage and synaptic change can be dissociated. Cocultures of Aplysia sensory and motor neurons were trained with spaced pulses of serotonin, which induces long-term facilitation. Serotonin (5HT) triggered growth of new presynaptic varicosities, a synaptic mechanism of long-term sensitization. Following 5HT training, two antimnemonic treatments—reconsolidation blockade and inhibition of PKM—caused the number of presynaptic varicosities to revert to the original, pretraining value. Surprisingly, the final synaptic structure was not achieved by targeted retraction of the 5HT-induced varicosities but, rather, by an apparently arbitrary retraction of both 5HT-induced and original synapses. In addition, we find evidence that the LTM for sensitization persists covertly after its apparent elimination by the same antimnemonic treatments that erase learning-related synaptic growth. These results challenge the idea that stable synapses store long-term memories.
Learning Resource Type Article
Publisher Date 2014-11-17
e-ISSN 2050084X
Journal eLife