CALCIUM CONTROL OF TRANSMITTER RELEASE AT A CEREBELLAR SYNAPSE

被引：439

作者：

MINTZ, IM ^{[1
]}

SABATINI, BL ^{[1
]}

REGEHR, WG ^{[1
]}

机构：

[1] HARVARD UNIV,SCH MED,DEPT NEUROBIOL,BOSTON,MA 02115

来源：

NEURON | 1995年 / 15卷 / 03期

关键词：

D O I：

10.1016/0896-6273(95)90155-8

中图分类号：

Q189 [神经科学];

学科分类号：

071006 ;

摘要：

The manner in which presynaptic Ca2+ influx controls the release of neurotransmitter was investigated at the granule cell to Purkinje cell synapse in rat cerebellar slices, Excitatory postsynaptic currents were measured using whole-cell voltage clamp, and changes in presynaptic Ca2+ influx were determined with the Ca2+-sensitive dye furaptra. We manipulated presynaptic Ca2+ entry by altering external Ca2+ levels and by blocking Ca2+ channels with Cd2+ or with the toxins omega-conotoxin GVIA and omega-Aga-IVA. For all of the manipulations, other than the application of omega-Aga-IVA, the relationship between Ca2+ influx and release was well approximated by a power law, n approximate to 2.5. When omega-Aga-IVA was applied, release appeared to be more steeply dependent on Ca2+ (n approximate to 4), suggesting that omega-Aga-IVA-sensitive channels are more effective at triggering release. Based on interactive effects of toxins on synaptic currents, we conclude that multiple types of Ca2+ channels synergistically control individual release sites.

引用

页码：675 / 688

页数：14

共 57 条

[41] MEASUREMENTS OF EXOCYTOSIS FROM SINGLE PRESYNAPTIC NERVE-TERMINALS REVEAL HETEROGENEOUS INHIBITION BY CA2+-CHANNEL BLOCKERS [J].