title: Interaction between long-term potentiation and depression in CA1 synapses: temporal constrains, functional compartmentalization and protein synthesis.
abstract: Information arriving at a neuron via anatomically defined pathways undergoes spatial and temporal encoding. A proposed mechanism by which temporally and spatially segregated information is encoded at the cellular level is based on the interactive properties of synapses located within and across functional dendritic compartments. We examined cooperative and interfering interactions between long-term synaptic potentiation (LTP) and depression (LTD), two forms of synaptic plasticity thought to be key in the encoding of information in the brain. Two approaches were used in CA1 pyramidal neurons of the mouse hippocampus: (1) induction of LTP and LTD in two separate synaptic pathways within the same apical dendritic compartment and across the basal and apical dendritic compartments; (2) induction of LTP and LTD separated by various time intervals (0-90 min). Expression of LTP/LTD interactions was spatially and temporally regulated. While they were largely restricted within the same dendritic compartment (compartmentalized), the nature of the interaction (cooperation or interference) depended on the time interval between inductions. New protein synthesis was found to regulate the expression of the LTP/LTD interference. We speculate that mechanisms for compartmentalization and protein synthesis confer the spatial and temporal modulation by which neurons encode multiplex information in plastic synapses.
authors.affiliation: Department of Pathology, State University of New York, Downstate Medical Center, Brooklyn, New York, United States of America.
authors.forename: Alice
authors.initials: A
authors.lastname: Pavlowsky
authors.forename: Juan Marcos
authors.initials: JM
authors.lastname: Alarcon
mesh_terms: D000818:Animals; D000841:Anisomycin / Q000494:pharmacology; D056547:CA1 Region, Hippocampal / Q000166:cytology / Q000502:physiology*; D003609:Dactinomycin / Q000494:pharmacology; D003712:Dendrites / Q000187:drug effects / Q000502:physiology; D004594:Electrophysiology / Q000379:methods; D066298:In Vitro Techniques; D017774:Long-Term Potentiation / Q000502:physiology*; D036881:Long-Term Synaptic Depression / Q000502:physiology*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D014176:Protein Biosynthesis / Q000187:drug effects / Q000502:physiology; D011500:Protein Synthesis Inhibitors / Q000494:pharmacology; D013569:Synapses / Q000187:drug effects / Q000502:physiology*; D013997:Time Factors
chemical_list: D011500:Protein Synthesis Inhibitors; D003609:Dactinomycin; D000841:Anisomycin