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Differential modulation of short‐term synaptic dynamics by long‐term potentiation at mouse hippocampal mossy fibre synapses
Author(s) -
Gundlfinger Anja,
Leibold Christian,
Gebert Katja,
Moisel Marion,
Schmitz Dietmar,
Kempter Richard
Publication year - 2007
Publication title -
the journal of physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.802
H-Index - 240
eISSN - 1469-7793
pISSN - 0022-3751
DOI - 10.1113/jphysiol.2007.143925
Subject(s) - long term potentiation , neuroscience , neural facilitation , synapse , synaptic plasticity , metaplasticity , hippocampal formation , neurotransmission , facilitation , synaptic augmentation , synaptic fatigue , excitatory postsynaptic potential , chemistry , biology , inhibitory postsynaptic potential , receptor , biochemistry
Synapses continuously experience short‐ and long‐lasting activity‐dependent changes in synaptic strength. Long‐term plasticity refers to persistent alterations in synaptic efficacy, whereas short‐term plasticity (STP) reflects the instantaneous and reversible modulation of synaptic strength in response to varying presynaptic stimuli. The hippocampal mossy fibre synapse onto CA3 pyramidal cells is known to exhibit both a presynaptic, NMDA receptor‐independent form of long‐term potentiation (LTP) and a pronounced form of STP. A detailed description of their exact interdependence is, however, lacking. Here, using electrophysiological and computational techniques, we have developed a descriptive model of transmission dynamics to quantify plasticity at the mossy fibre synapse. STP at this synapse is best described by two facilitatory processes acting on time‐scales of a few hundred milliseconds and about 10 s. We find that these distinct types of facilitation are differentially influenced by LTP such that the impact of the fast process is weakened as compared to that of the slow process. This attenuation is reflected by a selective decrease of not only the amplitude but also the time constant of the fast facilitation. We henceforth argue that LTP, involving a modulation of parameters determining both amplitude and time course of STP, serves as a mechanism to adapt the mossy fibre synapse to its temporal input.