title: Matched pre- and post-synaptic changes underlie synaptic plasticity over long time scales.
abstract: Modifications of synaptic efficacies are considered essential for learning and memory. However, it is not known how the underlying functional components of synaptic transmission change over long time scales. To address this question, we studied cortical synapses from young Wistar rats before and after 12 h intervals of spontaneous or glutamate-induced spiking activity. We found that, under these conditions, synaptic efficacies can increase or decrease by up to 10-fold. Statistical analyses reveal that these changes reflect modifications in the number of presynaptic release sites, together with postsynaptic changes that maintain the quantal size per release site. The quantitative relation between the presynaptic and postsynaptic transmission components was not affected when synaptic plasticity was enhanced or reduced using a broad range of pharmacological agents. These findings suggest that ongoing synaptic plasticity results in matched presynaptic and postsynaptic modifications, in which elementary modules that span the synaptic cleft are added or removed as a function of experience.
authors.affiliation: Faculty of Biology, Ludwig-Maxmilians-Universität München, and Bernstein Center for Computational Neuroscience, D-82152 Munich, Germany. alex.loebel@gmail.com
authors.forename: Alex
authors.initials: A
authors.lastname: Loebel
authors.forename: Jean-Vincent
authors.initials: JV
authors.lastname: Le Bé
authors.forename: Magnus J E
authors.initials: MJ
authors.lastname: Richardson
authors.forename: Henry
authors.initials: H
authors.lastname: Markram
authors.forename: Andreas V M
authors.initials: AV
authors.lastname: Herz
mesh_terms: D000818:Animals; D002540:Cerebral Cortex / Q000187:drug effects / Q000502:physiology; D019706:Excitatory Postsynaptic Potentials / Q000187:drug effects / Q000502:physiology*; D005260:Female; D018698:Glutamic Acid / Q000494:pharmacology; D006706:Homeostasis / Q000502:physiology*; D017774:Long-Term Potentiation / Q000502:physiology; D036881:Long-Term Synaptic Depression / Q000502:physiology; D008297:Male; D008959:Models, Neurological; D009473:Neuronal Plasticity / Q000502:physiology*; D017729:Presynaptic Terminals / Q000502:physiology*; D051381:Rats; D017208:Rats, Wistar; D009435:Synaptic Transmission / Q000502:physiology*; D013997:Time Factors
chemical_list: D018698:Glutamic Acid