| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
Biophysical Journal 48: 1003-1017 (1985)
© 1985 the Biophysical Society
ABSTRACT
A one-dimensional model of presynaptic calcium diffusion away from the membrane, with cytoplasmic binding, extrusion by a surface pump, and influx during action potentials, can account for the rapid decay of phasic transmitter release and the slower decay of synaptic facilitation following one spike, as well as the very slow decline in total free calcium observed experimentally. However, simulations using this model, and alternative versions in which calcium uptake into organelles and saturable binding are included, fail to preserve phasic transmitter release to spikes in a long tetanus. A three-dimensional diffusion model was developed, in which calcium enters through discrete membrane channels and acts to release transmitter within 50 nm of entry points. Analytic solutions of the equations of this model, in which calcium channels were distributed in active zone patches based on ultrastructural observations, were successful in predicting synaptic facilitation, phasic release to tetanic spikes, and the accumulation of total free calcium. The effects of varying calcium buffering, pump rate, and channel number and distribution were explored. Versions appropriate to squid giant synapses and frog neuromuscular junctions were simulated. Limitations of key assumptions, particularly rapid nonsaturable binding, are discussed.
This article has been cited by other articles:
 |
|
 |
|
  V. Shahrezaei and K. R. Delaney Brevity of the Ca2+ Microdomain and Active Zone Geometry Prevent Ca2+-Sensor Saturation for Neurotransmitter Release J Neurophysiol, September 1, 2005; 94(3): 1912 - 1919. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 M. D. Womack, C. Chevez, and K. Khodakhah Calcium-Activated Potassium Channels Are Selectively Coupled to P/Q-Type Calcium Channels in Cerebellar Purkinje Neurons J. Neurosci., October 6, 2004; 24(40): 8818 - 8822. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 V. Matveev, R. S. Zucker, and A. Sherman Facilitation through Buffer Saturation: Constraints on Endogenous Buffering Properties Biophys. J., May 1, 2004; 86(5): 2691 - 2709. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. Trommershauser, R. Schneggenburger, A. Zippelius, and E. Neher Heterogeneous Presynaptic Release Probabilities: Functional Relevance for Short-Term Plasticity Biophys. J., March 1, 2003; 84(3): 1563 - 1579. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 K. HU and B. DAVLETOV SNAREs and control of synaptic release probabilities FASEB J, February 1, 2003; 17(2): 130 - 135. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
T. D. Gover, X.-Y. Jiang, and T. W. Abrams Persistent, Exocytosis-Independent Silencing of Release Sites Underlies Homosynaptic Depression at Sensory Synapses in Aplysia J. Neurosci., March 1, 2002; 22(5): 1942 - 1955. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. K. Angleson and W. J. Betz Intraterminal Ca2+ and Spontaneous Transmitter Release at the Frog Neuromuscular Junction J Neurophysiol, January 1, 2001; 85(1): 287 - 294. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 R. Bertram Differential Filtering of Two Presynaptic Depression Mechanisms Neural Comput., January 1, 2001; 13(1): 69 - 85. [Abstract] [Full Text]
|
|
|
|
|
|
M. A. Xu-Friedman and W. G. Regehr Probing Fundamental Aspects of Synaptic Transmission with Strontium J. Neurosci., June 15, 2000; 20(12): 4414 - 4422. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. Vyshedskiy and J.-W. Lin Presynaptic Ca2+ Influx at the Inhibitor of the Crayfish Neuromuscular Junction: A Photometric Study at a High Time Resolution J Neurophysiol, January 1, 2000; 83(1): 552 - 562. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
D. A. DiGregorio, A. Peskoff, and J. L. Vergara Measurement of Action Potential-Induced Presynaptic Calcium Domains at a Cultured Neuromuscular Junction J. Neurosci., September 15, 1999; 19(18): 7846 - 7859. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
C. Chen and W. G. Regehr Contributions of Residual Calcium to Fast Synaptic Transmission J. Neurosci., August 1, 1999; 19(15): 6257 - 6266. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
R. Ravin, H. Parnas, M. E. Spira, N. Volfovsky, and I. Parnas Simultaneous Measurement of Evoked Release and [Ca2+]i in a Crayfish Release Bouton Reveals High Affinity of Release to Ca2+ J Neurophysiol, February 1, 1999; 81(2): 634 - 642. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. Qian and P. Saggau Modulation of Transmitter Release by Action Potential Duration at the Hippocampal CA3-CA1 Synapse J Neurophysiol, January 1, 1999; 81(1): 288 - 298. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
P. P. Atluri and W. G. Regehr Delayed Release of Neurotransmitter from Cerebellar Granule Cells J. Neurosci., October 15, 1998; 18(20): 8214 - 8227. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
B. L. Sabatini and W. G. Regehr Control of Neurotransmitter Release by Presynaptic Waveform at the Granule Cell to Purkinje Cell Synapse J. Neurosci., May 15, 1997; 17(10): 3425 - 3435. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 A Hernandez-Cruz, F Sala, and P. Adams Subcellular calcium transients visualized by confocal microscopy in a voltage-clamped vertebrate neuron Science, February 16, 1990; 247(4944): 858 - 862. [Abstract] [PDF]
|
|
|
|
|
|
R. Zucker and L Lando Mechanism of transmitter release: voltage hypothesis and calcium hypothesis Science, February 7, 1986; 231(4738): 574 - 579. [Abstract] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
