Abstract
Ultrastructural techniques and electron probe microanalysis were used to determine whether or not the smooth endoplasmic reticulum (SER) within presynaptic nerve terminals is a Ca-sequestering site. The three- dimensional structure of the SER was determined from serial sections of synaptosomes. The SER consists of flattened cisterns that may branch and are frequently juxtaposed to mitochondria. To investigate intraterminal Ca sequestration, synaptosomes were treated with saponin to disrupt the plasmalemmal permeability barrier. When these synaptosomes were incubated in solutions containing Ca, ATP, and oxalate, electrondense Ca oxalate deposits were found in intraterminal mitochondria, SER cisterns, and large vesicular profiles. Saponin- treated synaptosomes that were incubated in the presence of mitochondrial poisons contained electron-dense deposits within SER cisterns and large vesicular profiles, but very rarely in mitochondria. Similar deposits were observed within saponin-treated synaptosomes that were not post-fixed with OSO4, and within saponin-treated synaptosomes that were prepared for analysis by freeze-substitution. Electron-probe microanalyses of these deposits confirmed the presence of large concentrations of Ca. When oxalate was omitted from the incubation solutions, no electron-dense deposits were present in saponin-treated synaptosomes. In other control experiments, either the Ca ionophore A23187 or the Ca chelator EGTA was added to the incubation media; electron-dense deposits were very rarely observed within the intraterminal organelles of these saponin-treated synaptosomes. The data indicate that presynaptic nerve terminal SER is indeed a Ca- sequestering organelle.
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- Alnaes E., Rahamimoff R. On the role of mitochondria in transmitter release from motor nerve terminals. J Physiol. 1975 Jun;248(2):285–306. doi: 10.1113/jphysiol.1975.sp010974. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Baker P. F., Schlaepfer W. W. Uptake and binding of calcium by axoplasm isolated from giant axons of Loligo and Myxicola. J Physiol. 1978 Mar;276:103–125. doi: 10.1113/jphysiol.1978.sp012222. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Baskin R. J. Ultrastructure and calcium transport in crustacean muscle microsomes. J Cell Biol. 1971 Jan;48(1):49–60. doi: 10.1083/jcb.48.1.49. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Bird M. M. Presynaptic and postsynaptic organelles of synapses formed in cultures of previously dissociated mouse spinal cord. Cell Tissue Res. 1978 Dec 12;194(3):503–511. doi: 10.1007/BF00236169. [DOI] [PubMed] [Google Scholar]
- Blaustein M. P., Ector A. C. Carrier-mediated sodium-dependent and calcium-dependent calcium efflux from pinched-off presynaptic nerve terminals (synaptosomes) in vitro. Biochim Biophys Acta. 1976 Jan 21;419(2):295–308. doi: 10.1016/0005-2736(76)90355-2. [DOI] [PubMed] [Google Scholar]
- Blaustein M. P., Oborn C. J. The influence of sodium on calcium fluxes in pinched-off nerve terminals in vitro. J Physiol. 1975 Jun;247(3):657–686. doi: 10.1113/jphysiol.1975.sp010951. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Blaustein M. P., Ratzlaff R. W., Kendrick N. C., Schweitzer E. S. Calcium buffering in presynaptic nerve terminals. I. Evidence for involvement of a nonmitochondrial ATP-dependent sequestration mechanism. J Gen Physiol. 1978 Jul;72(1):15–41. doi: 10.1085/jgp.72.1.15. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Blaustein M. P., Ratzlaff R. W., Schweitzer E. S. Calcium buffering in presynaptic nerve terminals. II. Kinetic properties of the nonmitochondrial Ca sequestration mechanism. J Gen Physiol. 1978 Jul;72(1):43–66. doi: 10.1085/jgp.72.1.43. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Blitz A. L., Fine R. E., Toselli P. A. Evidence that coated vesicles isolated from brain are calcium-sequestering organelles resembling sarcoplasmic reticulum. J Cell Biol. 1977 Oct;75(1):135–147. doi: 10.1083/jcb.75.1.135. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Breckenridge W. C., Gombos G., Morgan I. G. The lipid composition of adult rat brain synaptosomal plasma membranes. Biochim Biophys Acta. 1972 Jun 20;266(3):695–707. doi: 10.1016/0006-3002(72)90012-1. [DOI] [PubMed] [Google Scholar]
- Breckenridge W. C., Morgan I. G., Zanetta J. P., Vincendon G. Adult rat brain synaptic vesicles. II. Lipid composition. Biochim Biophys Acta. 1973 Oct 5;320(3):681–686. doi: 10.1016/0304-4165(73)90148-7. [DOI] [PubMed] [Google Scholar]
- Carsten M. E., Reedy M. K. Cardiac sarcoplasmic reticulum: chemical and electron microscope studies of calcium accumulation. J Ultrastruct Res. 1971 Jun;35(5):554–574. doi: 10.1016/s0022-5320(71)80011-4. [DOI] [PubMed] [Google Scholar]
- Devine C. E., Somlyo A. V., Somlyo A. P. Sarcoplasmic reticulum and excitation-contraction coupling in mammalian smooth muscles. J Cell Biol. 1972 Mar;52(3):690–718. doi: 10.1083/jcb.52.3.690. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Droz B., Rambourg A., Koenig H. L. The smooth endoplasmic reticulum: structure and role in the renewal of axonal membrane and synaptic vesicles by fast axonal transport. Brain Res. 1975 Jul 25;93(1):1–13. doi: 10.1016/0006-8993(75)90282-6. [DOI] [PubMed] [Google Scholar]
- Eckert R., Tillotson D. Potassium activation associated with intraneuronal free calcium. Science. 1978 Apr 28;200(4340):437–439. doi: 10.1126/science.644308. [DOI] [PubMed] [Google Scholar]
- Eroglu L., Keen P. Active uptake of 45Ca by a microsomal fraction prepared from rat dorsal roots. J Neurochem. 1977 Nov;29(5):905–909. doi: 10.1111/j.1471-4159.1977.tb10734.x. [DOI] [PubMed] [Google Scholar]
- Erulkar S. D., Rahamimoff R. The role of calcium ions in tetanic and post-tetanic increase of miniature end-plate potential frequency. J Physiol. 1978 May;278:501–511. doi: 10.1113/jphysiol.1978.sp012320. [DOI] [PMC free article] [PubMed] [Google Scholar]
- FEDER N., SIDMAN R. L. Methods and principles of fixation by freeze-substitution. J Biophys Biochem Cytol. 1958 Sep 25;4(5):593–600. doi: 10.1083/jcb.4.5.593. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Gambetti P., Erulkar S. E., Somlyo A. P., Gonatas N. K. Calcium-containing structures in vertebrate glial cells. Ultrastructural and microprobe analysis. J Cell Biol. 1975 Feb;64(2):322–330. doi: 10.1083/jcb.64.2.322. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Gray E. G., Paula-Barbosa M. Dense particles within synaptic vesicles fixed with acid-aldehyde. J Neurocytol. 1974 Oct;3(4):487–496. doi: 10.1007/BF01098735. [DOI] [PubMed] [Google Scholar]
- Hales C. N., Luzio J. P., Chandler J. A., Herman L. Localization of calcium in the smooth endoplasmic reticulum of rat isolated fat cells. J Cell Sci. 1974 Jun;15(1):1–15. doi: 10.1242/jcs.15.1.1. [DOI] [PubMed] [Google Scholar]
- Harreveld A. V., Fifkova E. Rapid freezing of deep cerebral structures for electron microscopy. Anat Rec. 1975 Jul;182(3):377–385. doi: 10.1002/ar.1091820311. [DOI] [PubMed] [Google Scholar]
- Henkart M. P., Reese T. S., Brinley F. J., Jr Endoplasmic reticulum sequesters calcium in the squid giant axon. Science. 1978 Dec 22;202(4374):1300–1303. doi: 10.1126/science.725607. [DOI] [PubMed] [Google Scholar]
- Henkart M., Landis D. M., Reese T. S. Similarity of junctions between plasma membranes and endoplasmic reticulum in muscle and neurons. J Cell Biol. 1976 Aug;70(2 Pt 1):338–347. doi: 10.1083/jcb.70.2.338. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Katz B., Miledi R. Tetrodotoxin-resistant electric activity in presynaptic terminals. J Physiol. 1969 Aug;203(2):459–487. doi: 10.1113/jphysiol.1969.sp008875. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Katz B., Miledi R. The role of calcium in neuromuscular facilitation. J Physiol. 1968 Mar;195(2):481–492. doi: 10.1113/jphysiol.1968.sp008469. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Kendrick N. C., Blaustein M. P., Fried R. C., Ratzlaff R. W. ATP-dependent calcium storage in presynaptic nerve terminals. Nature. 1977 Jan 20;265(5591):246–248. doi: 10.1038/265246a0. [DOI] [PubMed] [Google Scholar]
- Korn E. D. Cell membranes: structure and synthesis. Annu Rev Biochem. 1969;38:263–288. doi: 10.1146/annurev.bi.38.070169.001403. [DOI] [PubMed] [Google Scholar]
- Kretsinger R. H. Calcium-binding proteins. Annu Rev Biochem. 1976;45:239–266. doi: 10.1146/annurev.bi.45.070176.001323. [DOI] [PubMed] [Google Scholar]
- Lazarewicz J. W., Haljamäe H., Hamberger A. Calcium metabolism in isolated brain cells and subcellular fractions. J Neurochem. 1974 Jan;22(1):33–45. doi: 10.1111/j.1471-4159.1974.tb12176.x. [DOI] [PubMed] [Google Scholar]
- Lieberman A. R. Microtubule-associated smooth endoplasmic reticulum in the frog's brain. Z Zellforsch Mikrosk Anat. 1971;116(4):564–577. doi: 10.1007/BF00335058. [DOI] [PubMed] [Google Scholar]
- Llinás R. R. Depolarization-release coupling systems in neurons. Neurosci Res Program Bull. 1977 Dec;15(4):555–687. [PubMed] [Google Scholar]
- Llinás R., Nicholson C. Calcium role in depolarization-secretion coupling: an aequorin study in squid giant synapse. Proc Natl Acad Sci U S A. 1975 Jan;72(1):187–190. doi: 10.1073/pnas.72.1.187. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Loud A. V. A quantitative stereological description of the ultrastructure of normal rat liver parenchymal cells. J Cell Biol. 1968 Apr;37(1):27–46. doi: 10.1083/jcb.37.1.27. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Meech R. W. Calcium-dependent potassium activation in nervous tissues. Annu Rev Biophys Bioeng. 1978;7:1–18. doi: 10.1146/annurev.bb.07.060178.000245. [DOI] [PubMed] [Google Scholar]
- Miledi R. Transmitter release induced by injection of calcium ions into nerve terminals. Proc R Soc Lond B Biol Sci. 1973 Jul 3;183(1073):421–425. doi: 10.1098/rspb.1973.0026. [DOI] [PubMed] [Google Scholar]
- Ochs S., Worth R. M., Chan S. Y. Calcium requirement for axoplasmic transport in mammalian nerve. Nature. 1977 Dec 22;270(5639):748–750. doi: 10.1038/270748a0. [DOI] [PubMed] [Google Scholar]
- Pappas G. D., Rose S. Localization of calcium deposits in the frog neuromuscular junction at rest and following stimulation. Brain Res. 1976 Feb 20;103(2):362–365. doi: 10.1016/0006-8993(76)90806-4. [DOI] [PubMed] [Google Scholar]
- Robinson J. D., Lust W. D. Adenosine triophosphate-dependent calcium accumulation by brain microsomes. Arch Biochem Biophys. 1968 Apr;125(1):286–294. doi: 10.1016/0003-9861(68)90663-2. [DOI] [PubMed] [Google Scholar]
- Schliwa M. The role of divalent cations in the regulation of microtubule assembly. In vivo studies on microtubules of the heliozoan axopodium using the ionophore A23187. J Cell Biol. 1976 Sep;70(3):527–540. doi: 10.1083/jcb.70.3.527. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Shuman H., Somlyo A. V., Somlyo A. P. Quantitative electron probe microanalysis of biological thin sections: methods and validity. Ultramicroscopy. 1976 Sep-Oct;1(4):317–339. doi: 10.1016/0304-3991(76)90049-8. [DOI] [PubMed] [Google Scholar]
- Simson J. A., Spicer S. S. Selective subcellular localization of cations with variants of the potassium (pyro)antimonate technique. J Histochem Cytochem. 1975 Aug;23(8):575–598. doi: 10.1177/23.8.51037. [DOI] [PubMed] [Google Scholar]
- Somlyo A. P., Devine C. E., Somlyo A. V., North S. R. Sarcoplasmic reticulum and the temperature-dependent contraction of smooth muscle in calcium-free solutions. J Cell Biol. 1971 Dec;51(3):722–741. doi: 10.1083/jcb.51.3.722. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Somlyo A. P., Somlyo A. V., Shuman H. Electron probe analysis of vascular smooth muscle. Composition of mitochondria, nuclei, and cytoplasm. J Cell Biol. 1979 May;81(2):316–335. doi: 10.1083/jcb.81.2.316. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Somlyo A. V., Shuman H., Somlyo A. P. Elemental distribution in striated muscle and the effects of hypertonicity. Electron probe analysis of cryo sections. J Cell Biol. 1977 Sep;74(3):828–857. doi: 10.1083/jcb.74.3.828. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Stoeckel M. E., Hindelang-Gertner C., Dellmann H-D, Porte A., Stutinsky F. Subcellular localization of calcium in the mouse hypophysis. I. Calcium distribution in the adeno- and neurohypophysis under normal conditions. Cell Tissue Res. 1975;157(3):307–322. doi: 10.1007/BF00225522. [DOI] [PubMed] [Google Scholar]
- Trotta E. E., de Meis L. ATP-dependent calcium accumulation in brain microsomes. Enhancement by phosphate and oxalate. Biochim Biophys Acta. 1975 Jun 25;394(2):239–247. doi: 10.1016/0005-2736(75)90262-x. [DOI] [PubMed] [Google Scholar]
- Weinreich D. Ionic mechanism of post-tetanic potentiation at the neuromuscular junction of the frog. J Physiol. 1971 Jan;212(2):431–446. doi: 10.1113/jphysiol.1971.sp009333. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Younkin S. G. An analysis of the role of calcium in facilitation at the frog neuromuscular junction. J Physiol. 1974 Feb;237(1):1–14. doi: 10.1113/jphysiol.1974.sp010466. [DOI] [PMC free article] [PubMed] [Google Scholar]