Late-associativity, synaptic tagging, and the role of dopamine during LTP and LTD

Neurobiol Learn Mem. 2004 Jul;82(1):12-25. doi: 10.1016/j.nlm.2004.03.003.


Protein synthesis-dependent, synapse input-specific late phases of long-term potentiation (LTP) and depression (LTD) may underlie memory formation at the cellular level. Recently, it was described that the induction of LTP can mark a specifically activated synapse by a synaptic tag to capture synapse non-specific plasticity-related proteins (PRPs) and thus maintaining input-specific LTP for prolonged periods. Here we show in rat hippocampal slices in vitro, that the induction of protein synthesis-dependent late-LTD is also characterized by synaptic tagging and that heterosynaptic induction of either LTD or LTP on two sets of independent synaptic inputs S1 and S2 can lead to late-associative interactions: early-LTD in S2 was transformed into a late-LTD, if late-LTP was induced in S1. The synthesis of process-independent PRPs by late-LTP in S1 was sufficient to transform early- into late-LTD in S2 when process-specific synaptic tags were set. We name this new associative property of cellular information processing 'cross-tagging.'

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cell Communication / physiology
  • Dopamine / metabolism*
  • Electric Stimulation
  • Hippocampus / cytology
  • Hippocampus / metabolism*
  • Long-Term Potentiation / physiology*
  • Long-Term Synaptic Depression / physiology*
  • Male
  • Models, Neurological
  • Nerve Tissue Proteins / biosynthesis
  • Neuronal Plasticity / physiology
  • Neurons / metabolism*
  • Organ Culture Techniques
  • Rats
  • Rats, Wistar
  • Synapses / physiology*


  • Nerve Tissue Proteins
  • Dopamine