Developmental changes in calcium channel types mediating central synaptic transmission

Multiple types of high-voltage-activated Ca2+ channels trigger neurotransmitter release at the mammalian central synapse. Among them, the ω-conotoxin GVIA-sensitive N-type channels and the ω-Aga-IVA-sensitive P/Q- type channels mediate fast synaptic transmission. However, at most central synapses, i...

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Detalles Bibliográficos
Autores principales: Iwasaki, S., Momiyama, A., Uchitel, O.D., Takahashi, T.
Formato: JOUR
Materias:
Central synapse
N-type calcium channels
P/Q-type calcium channels
Postnatal development
Slice
Transmitter release
calcium channel
neurotransmitter
omega conotoxin
animal tissue
article
brain cortex
calcium current
controlled study
GABAergic system
nerve ending
neurotransmitter release
nonhuman
postnatal development
priority journal
rat
spinal cord dorsal horn
synapse
synaptic transmission
2-Amino-5-phosphonovalerate
6-Cyano-7-nitroquinoxaline-2,3-dione
Age Factors
Animals
Brain Chemistry
Calcium Channel Blockers
Calcium Channels, N-Type
Calcium Channels, R-Type
Central Nervous System
Evoked Potentials
Excitatory Amino Acid Antagonists
Excitatory Postsynaptic Potentials
gamma-Aminobutyric Acid
Glycine Agents
omega-Agatoxin IVA
omega-Conotoxins
Organ Culture Techniques
Rats
Rats, Wistar
Strychnine
Synaptic Transmission
Acceso en línea:http://hdl.handle.net/20.500.12110/paper_02706474_v20_n1_p59_Iwasaki
Aporte de:
Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) de Universidad de Buenos Aires
Descripción
Sumario:Multiple types of high-voltage-activated Ca2+ channels trigger neurotransmitter release at the mammalian central synapse. Among them, the ω-conotoxin GVIA-sensitive N-type channels and the ω-Aga-IVA-sensitive P/Q- type channels mediate fast synaptic transmission. However, at most central synapses, it is not known whether the contributions of different Ca2+ channel types to synaptic transmission remain stable throughout postnatal development. We have addressed this question by testing type-specific Ca2+ channel blockers at developing central synapses. Our results indicate that N- type channels contribute to thalamic and cerebellar IPSCs only transiently during early postnatal period and P/Q-type channels predominantly mediate mature synaptic transmission, as we reported previously at the brainstem auditory synapse formed by the calyx of Held. In fact, Ca2+ currents directly recorded from the auditory calyceal presynaptic terminal were identified as N-, P/Q-, and R-types at postnatal day 7 (P7) to P10 but became predominantly P/Q-type at P13. In contrast to thalamic and cerebellar IPSCs and brainstem auditory EPSCs, N-type Ca2+ channels persistently contribute to cerebral cortical EPSCs and spinal IPSCs throughout postnatal months. Thus, in adult animals, synaptic transmission is predominantly mediated by P/Q-type channels at a subset of synapses and mediated synergistically by multiple types of Ca2+ channels at other synapses.

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