Making Memories

See allHide authors and affiliations

Science  14 Jan 2005:
Vol. 307, Issue 5707, pp. 182
DOI: 10.1126/science.307.5707.182b

During learning, in a process termed long-term potentiation or long-term facilitation, synapses are specifically modified by a process that involves transcription. Because the synapse itself is at a distance from the neuronal cell nucleus—separated by the elongated axon or dendrite—the neuron must possess mechanisms to transmit synaptically activated second messengers and transcription factors to its nucleus. Thomson et al. now dissect aspects of this pathway in Aplysia sensory neurons and in mouse hippocampal neurons. In both cases importins (proteins involved in active nuclear import in many cell types) appear to be involved. In both types of neurons, importins were found localized along axons and dendrites and in synaptic compartments. Stimuli that triggered long-lasting facilitation in Aplysia triggered translocation of importin to the nucleus. Similarly, in hippocampal neurons synaptic receptor activation promoted nuclear accumulation of importin. The changes in importin distribution were not observed when only short-term synaptic changes were induced (changes that are known not to involve changes in transcription). It remains to be demonstrated which memory-related substrates may be associated with the translocating importins, but a role for the classical nuclear import pathway in generating long-lasting memories seems likely. — SMH

Neuron 44, 997 (2004).


Navigate This Article