251. Functional Specialization of Presynaptic Cav2.3 Ca2+ Channels
- Author
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Toni Schneider, Alexej Pereverzev, Timo Kirschstein, Christian von der Brelie, Dirk Dietrich, Heinz Beck, and Maria Kukley
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Male ,Mossy fiber (hippocampus) ,Neuroscience(all) ,Long-Term Potentiation ,Presynaptic Terminals ,Neural facilitation ,Mice, Transgenic ,Calcium Channels, R-Type ,Neurotransmission ,Biology ,Hippocampus ,Mice ,chemistry.chemical_compound ,Nickel ,Animals ,Neurotransmitter ,Neuronal Plasticity ,General Neuroscience ,Excitatory Postsynaptic Potentials ,Long-term potentiation ,Mice, Inbred C57BL ,Electrophysiology ,chemistry ,Synaptic plasticity ,Facilitation ,Calcium ,Calcium Channels ,Neuroscience - Abstract
Ca2+ influx into presynaptic terminals via voltage-dependent Ca2+ channels triggers fast neurotransmitter release as well as different forms of synaptic plasticity. Using electrophysiological and genetic techniques we demonstrate that presynaptic Ca2+ entry through Cav2.3 subunits contributes to the induction of mossy fiber LTP and posttetanic potentiation by brief trains of presynaptic action potentials while they do not play a role in fast synaptic transmission, paired-pulse facilitation, or frequency facilitation. This functional specialization is most likely achieved by a localization remote from the release machinery and by a Cav2.3 channel-dependent facilitation of presynaptic Ca2+ influx. Thus, the presence of Cav2.3 channels boosts the accumulation of presynaptic Ca2+ triggering presynaptic LTP and posttetanic potentiation without affecting the low release probability that is a prerequisite for the enormous plasticity displayed by mossy fiber synapses.
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