PT - JOURNAL ARTICLE AU - Shinichi Iwasaki AU - Akiko Momiyama AU - Osvaldo D. Uchitel AU - Tomoyuki Takahashi TI - Developmental Changes in Calcium Channel Types Mediating Central Synaptic Transmission AID - 10.1523/JNEUROSCI.20-01-00059.2000 DP - 2000 Jan 01 TA - The Journal of Neuroscience PG - 59--65 VI - 20 IP - 1 4099 - http://www.jneurosci.org/content/20/1/59.short 4100 - http://www.jneurosci.org/content/20/1/59.full SO - J. Neurosci.2000 Jan 01; 20 AB - 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.