Calcium influx and calcium current in single synaptic terminals of goldfish retinal bipolar neurons.
نویسندگان
چکیده
منابع مشابه
Calcium-dependent inactivation of calcium current in synaptic terminals of retinal bipolar neurons.
Giant synaptic terminals (approximately 10 micrometer diameter) of bipolar neurons from goldfish retina were used to directly investigate calcium-dependent inactivation of presynaptic calcium current. During sustained depolarization, calcium current was initially constant for a period lasting up to several hundred milliseconds and then it declined exponentially. The duration of the initial dela...
متن کاملUltrafast Exocytosis Elicited by Calcium Current in Synaptic Terminals of Retinal Bipolar Neurons
Using high resolution capacitance measurements, we have characterized an ultrafast component of transmitter release in ribbon-type synaptic terminals of retinal bipolar neurons. During depolarization, capacitance increases to a plateau of approximately 30 fF with a time constant of approximately 1.5 ms. When not limited by activation kinetics of calcium current, the small pool is depleted even ...
متن کاملMultiple GABA receptor subtypes mediate inhibition of calcium influx at rat retinal bipolar cell terminals.
Inhibitory effects of GABA on K(+)-evoked Ca2+ influx into rat retinal bipolar cell terminals were studied using calcium imaging methods. Application of high K+ evokes a sustained, reversible increase in [Ca2+]i at bipolar cell terminals, which occurs mainly via dihydropyridine-sensitive (L-type) Ca2+ channels. There are at least two GABA receptor subtypes coexisting at bipolar cell terminals: ...
متن کاملLateral mobility of L-type calcium channels in synaptic terminals of retinal bipolar cells
PURPOSE Efficient and precise release of glutamate from retinal bipolar cells is ensured by the positioning of L-type Ca(2+) channels close to release sites at the base of the synaptic ribbon. We investigated whether Ca(2+) channels at bipolar cell ribbon synapses are fixed in position or capable of moving in the membrane. METHODS We tracked the movements of individual L-type Ca(2+) channels ...
متن کاملCalcium influx selects the fast mode of endocytosis in the synaptic terminal of retinal bipolar cells.
To investigate the regulation of endocytosis by Ca(2+), we have made capacitance measurements in the synaptic terminal of depolarizing bipolar cells from the retina of goldfish. After a brief depolarization, all of the excess membrane was retrieved rapidly (tau approximately 1 s). But when the rise in free [Ca(2+)] was reduced by the introduction of Ca(2+) buffers [1,2-bis(2-aminophenoxy)ethane...
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ژورنال
عنوان ژورنال: The Journal of Physiology
سال: 1992
ISSN: 0022-3751
DOI: 10.1113/jphysiol.1992.sp019000