Functional specialization of presynaptic Cav2.3 Ca2+ channels.
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.
Dietrich
Dirk
D
Department of Neurosurgery, University Bonn, Sigmund-Freud Str. 25, 53105 Bonn, Germany. dirk.dietrich@ukb.uni-bonn.de
Kirschstein
Timo
T
Kukley
Maria
M
Pereverzev
Alexej
A
von der Brelie
Christian
C
Schneider
Toni
T
Beck
Heinz
H
D000818:Animals; D002118:Calcium / Q000502:physiology; D015220:Calcium Channels / Q000235:genetics / Q000502:physiology; D020908:Calcium Channels, R-Type / Q000235:genetics / Q000502:physiology*; D019706:Excitatory Postsynaptic Potentials / Q000502:physiology; D006624:Hippocampus / Q000502:physiology; D017774:Long-Term Potentiation / Q000502:physiology; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D009473:Neuronal Plasticity / Q000502:physiology; D009532:Nickel / Q000502:physiology; D017729:Presynaptic Terminals / Q000502:physiology*
D015220:Calcium Channels; D020908:Calcium Channels, R-Type; D009532:Nickel; D002118:Calcium