title: Late-associativity, synaptic tagging, and the role of dopamine during LTP and LTD.
abstract: 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.'
authors.affiliation: Department for Neurophysiology, Leibniz-Institute for Neurobiology, Brenneckestr. 6, D-39118 Magdeburg, Germany.
authors.forename: Sreedharan
authors.initials: S
authors.lastname: Sajikumar
authors.forename: Julietta U
authors.initials: JU
authors.lastname: Frey
mesh_terms: D000818:Animals; D002450:Cell Communication / Q000502:physiology; D004298:Dopamine / Q000378:metabolism*; D004558:Electric Stimulation; D006624:Hippocampus / Q000166:cytology / Q000378:metabolism*; D017774:Long-Term Potentiation / Q000502:physiology*; D036881:Long-Term Synaptic Depression / Q000502:physiology*; D008297:Male; D008959:Models, Neurological; D009419:Nerve Tissue Proteins / Q000096:biosynthesis; D009473:Neuronal Plasticity / Q000502:physiology; D009474:Neurons / Q000378:metabolism*; D009924:Organ Culture Techniques; D051381:Rats; D017208:Rats, Wistar; D013569:Synapses / Q000502:physiology*
chemical_list: D009419:Nerve Tissue Proteins; D004298:Dopamine