Abstract
1. The calcium indicator dye, indo-1, was used to analyse the receptor-specific mechanisms of intracellular calcium ion ([Ca2+]i) responses evoked by excitatory amino acid (EAA) stimulation of dorsal horn neurons. Measurements of somal changes in [Ca2+]i were made on a subsecond time scale under conditions designed to allow membrane potential to mediate interactions between agonist-gated channels and voltage-gated calcium channels (VGCCs). 2. Voltage-gated calcium channels were activated in a receptor-independent manner using elevated extracellular [K+]. The concentration-dependence of K(+)-evoked [Ca2+]i transients was steep and variable among cells, with a mean maximal [Ca2+]i response of 1400 nM and a rapid maximal rate of rise. These data indicate that VGCCs provide a high-capacity route for Ca2+ entry that is very sensitive to small changes in membrane potential. 3. Stimulation of non-NMDA receptors using the non-desensitizing agonist kainate also evoked large [Ca2+]i responses (mean, 840 nM) that were predominantly due to indirect activation of VGCCs. However, in 60% of neurons tested, a component of the [Ca2+]i transient evoked by kainate at concentrations above 10 microM was not blocked by the potent VGCC blocker, lanthanum (La3+). The La(3+)-resistant [Ca2+]i responses to kainate rose exponentially, required extracellular Ca2+, and were caused neither by evoked release of EAA transmitters nor by reversal of Na(+)-Ca2+ exchange. These responses may be mediated by a Ca(2+)-permeable conformation of non-NMDA receptors and can also be evoked by quisqualate, (S)-alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid (AMPA) and glutamate. 4. Non-NMDA receptors were activated in a desensitizing manner using quisqualate or AMPA. Quisqualate evoked small [Ca2+]i transients (210 nM) with a slow rate of rise. Typically, above 3 microM quisqualate, the size of the responses decreased, reflecting desensitization of the receptor. Responses to quisqualate were blocked by removal of extracellular Ca2+ indicating that mobilization of intracellular Ca2+ stores does not occur in the majority of dorsal horn neurons. However, trans-(+-)-1-amino-1,3-cyclopentane dicarboxylic acid (trans-ACPD) was occasionally able to evoke modest Ca2+ release. 5. Activation of the Ca(2+)-permeable NMDA receptors evoked [Ca2+]i transients that were large (780 nM), with a moderate rate of rise, and that generally achieved a maximum amplitude at NMDA concentrations around 300 microM. 6. Glutamate was used to examine [Ca2+]i responses to the activation of mixed EAA receptor subtypes by an endogenous ligand.(ABSTRACT TRUNCATED AT 400 WORDS)
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- Bezprozvanny I., Watras J., Ehrlich B. E. Bell-shaped calcium-response curves of Ins(1,4,5)P3- and calcium-gated channels from endoplasmic reticulum of cerebellum. Nature. 1991 Jun 27;351(6329):751–754. doi: 10.1038/351751a0. [DOI] [PubMed] [Google Scholar]
- Bixby J. L., Spitzer N. C. Early differentiation of vertebrate spinal neurons in the absence of voltage-dependent Ca2+ and Na+ influx. Dev Biol. 1984 Nov;106(1):89–96. doi: 10.1016/0012-1606(84)90065-4. [DOI] [PubMed] [Google Scholar]
- Boulter J., Hollmann M., O'Shea-Greenfield A., Hartley M., Deneris E., Maron C., Heinemann S. Molecular cloning and functional expression of glutamate receptor subunit genes. Science. 1990 Aug 31;249(4972):1033–1037. doi: 10.1126/science.2168579. [DOI] [PubMed] [Google Scholar]
- Dickenson A. H. A cure for wind up: NMDA receptor antagonists as potential analgesics. Trends Pharmacol Sci. 1990 Aug;11(8):307–309. doi: 10.1016/0165-6147(90)90228-z. [DOI] [PubMed] [Google Scholar]
- Egebjerg J., Bettler B., Hermans-Borgmeyer I., Heinemann S. Cloning of a cDNA for a glutamate receptor subunit activated by kainate but not AMPA. Nature. 1991 Jun 27;351(6329):745–748. doi: 10.1038/351745a0. [DOI] [PubMed] [Google Scholar]
- Faden A. I., Simon R. P. A potential role for excitotoxins in the pathophysiology of spinal cord injury. Ann Neurol. 1988 Jun;23(6):623–626. doi: 10.1002/ana.410230618. [DOI] [PubMed] [Google Scholar]
- Grynkiewicz G., Poenie M., Tsien R. Y. A new generation of Ca2+ indicators with greatly improved fluorescence properties. J Biol Chem. 1985 Mar 25;260(6):3440–3450. [PubMed] [Google Scholar]
- Henzi V., MacDermott A. B. Characteristics and function of Ca(2+)- and inositol 1,4,5-trisphosphate-releasable stores of Ca2+ in neurons. Neuroscience. 1992;46(2):251–273. doi: 10.1016/0306-4522(92)90049-8. [DOI] [PubMed] [Google Scholar]
- Hollmann M., Hartley M., Heinemann S. Ca2+ permeability of KA-AMPA--gated glutamate receptor channels depends on subunit composition. Science. 1991 May 10;252(5007):851–853. doi: 10.1126/science.1709304. [DOI] [PubMed] [Google Scholar]
- Holopainen I., Enkvist M. O., Akerman K. E. Glutamate receptor agonists increase intracellular Ca2+ independently of voltage-gated Ca2+ channels in rat cerebellar granule cells. Neurosci Lett. 1989 Mar 13;98(1):57–62. doi: 10.1016/0304-3940(89)90373-x. [DOI] [PubMed] [Google Scholar]
- Holopainen I., Louve M., Enkvist M. O., Akerman K. E. Coupling of glutamatergic receptors to changes in intracellular Ca2+ in rat cerebellar granule cells in primary culture. J Neurosci Res. 1990 Feb;25(2):187–193. doi: 10.1002/jnr.490250206. [DOI] [PubMed] [Google Scholar]
- Huang L. Y. Calcium channels in isolated rat dorsal horn neurones, including labelled spinothalamic and trigeminothalamic cells. J Physiol. 1989 Apr;411:161–177. doi: 10.1113/jphysiol.1989.sp017566. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Hume R. I., Dingledine R., Heinemann S. F. Identification of a site in glutamate receptor subunits that controls calcium permeability. Science. 1991 Aug 30;253(5023):1028–1031. doi: 10.1126/science.1653450. [DOI] [PubMed] [Google Scholar]
- Iino M., Ozawa S., Tsuzuki K. Permeation of calcium through excitatory amino acid receptor channels in cultured rat hippocampal neurones. J Physiol. 1990 May;424:151–165. doi: 10.1113/jphysiol.1990.sp018060. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Johnson J. W., Ascher P. Glycine potentiates the NMDA response in cultured mouse brain neurons. Nature. 1987 Feb 5;325(6104):529–531. doi: 10.1038/325529a0. [DOI] [PubMed] [Google Scholar]
- Keinänen K., Wisden W., Sommer B., Werner P., Herb A., Verdoorn T. A., Sakmann B., Seeburg P. H. A family of AMPA-selective glutamate receptors. Science. 1990 Aug 3;249(4968):556–560. doi: 10.1126/science.2166337. [DOI] [PubMed] [Google Scholar]
- Llano I., Dreessen J., Kano M., Konnerth A. Intradendritic release of calcium induced by glutamate in cerebellar Purkinje cells. Neuron. 1991 Oct;7(4):577–583. doi: 10.1016/0896-6273(91)90370-f. [DOI] [PubMed] [Google Scholar]
- MacDermott A. B., Mayer M. L., Westbrook G. L., Smith S. J., Barker J. L. NMDA-receptor activation increases cytoplasmic calcium concentration in cultured spinal cord neurones. 1986 May 29-Jun 4Nature. 321(6069):519–522. doi: 10.1038/321519a0. [DOI] [PubMed] [Google Scholar]
- Mayer M. L., MacDermott A. B., Westbrook G. L., Smith S. J., Barker J. L. Agonist- and voltage-gated calcium entry in cultured mouse spinal cord neurons under voltage clamp measured using arsenazo III. J Neurosci. 1987 Oct;7(10):3230–3244. doi: 10.1523/JNEUROSCI.07-10-03230.1987. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Mayer M. L., Vyklicky L., Jr, Clements J. Regulation of NMDA receptor desensitization in mouse hippocampal neurons by glycine. Nature. 1989 Mar 30;338(6214):425–427. doi: 10.1038/338425a0. [DOI] [PubMed] [Google Scholar]
- Mayer M. L., Westbrook G. L. The action of N-methyl-D-aspartic acid on mouse spinal neurones in culture. J Physiol. 1985 Apr;361:65–90. doi: 10.1113/jphysiol.1985.sp015633. [DOI] [PMC free article] [PubMed] [Google Scholar]
- McMillian M., Pritchard G. A., Miller L. G. Characterization of Ca2(+)-mobilizing excitatory amino acid receptors in cultured chick cortical cells. Eur J Pharmacol. 1990 Oct 30;189(4-5):253–266. doi: 10.1016/0922-4106(90)90118-h. [DOI] [PubMed] [Google Scholar]
- Murphy S. N., Miller R. J. A glutamate receptor regulates Ca2+ mobilization in hippocampal neurons. Proc Natl Acad Sci U S A. 1988 Nov;85(22):8737–8741. doi: 10.1073/pnas.85.22.8737. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Murphy S. N., Miller R. J. Regulation of Ca++ influx into striatal neurons by kainic acid. J Pharmacol Exp Ther. 1989 Apr;249(1):184–193. [PubMed] [Google Scholar]
- Murphy S. N., Miller R. J. Two distinct quisqualate receptors regulate Ca2+ homeostasis in hippocampal neurons in vitro. Mol Pharmacol. 1989 May;35(5):671–680. [PubMed] [Google Scholar]
- Murphy S. N., Thayer S. A., Miller R. J. The effects of excitatory amino acids on intracellular calcium in single mouse striatal neurons in vitro. J Neurosci. 1987 Dec;7(12):4145–4158. doi: 10.1523/JNEUROSCI.07-12-04145.1987. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Ogura A., Akita K., Kudo Y. Non-NMDA receptor mediates cytoplasmic Ca2+ elevation in cultured hippocampal neurones. Neurosci Res. 1990 Nov;9(2):103–113. doi: 10.1016/0168-0102(90)90026-b. [DOI] [PubMed] [Google Scholar]
- Patneau D. K., Mayer M. L. Structure-activity relationships for amino acid transmitter candidates acting at N-methyl-D-aspartate and quisqualate receptors. J Neurosci. 1990 Jul;10(7):2385–2399. doi: 10.1523/JNEUROSCI.10-07-02385.1990. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Reichling D. B., MacDermott A. B. Lanthanum actions on excitatory amino acid-gated currents and voltage-gated calcium currents in rat dorsal horn neurons. J Physiol. 1991 Sep;441:199–218. doi: 10.1113/jphysiol.1991.sp018746. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Sommer B., Keinänen K., Verdoorn T. A., Wisden W., Burnashev N., Herb A., Köhler M., Takagi T., Sakmann B., Seeburg P. H. Flip and flop: a cell-specific functional switch in glutamate-operated channels of the CNS. Science. 1990 Sep 28;249(4976):1580–1585. doi: 10.1126/science.1699275. [DOI] [PubMed] [Google Scholar]
- Stephenson D. G., Williams D. A. Calcium-activated force responses in fast- and slow-twitch skinned muscle fibres of the rat at different temperatures. J Physiol. 1981 Aug;317:281–302. doi: 10.1113/jphysiol.1981.sp013825. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Trosper T. L., Philipson K. D. Effects of divalent and trivalent cations on Na+-Ca2+ exchange in cardiac sarcolemmal vesicles. Biochim Biophys Acta. 1983 May 26;731(1):63–68. doi: 10.1016/0005-2736(83)90398-x. [DOI] [PubMed] [Google Scholar]
- Verdoorn T. A., Burnashev N., Monyer H., Seeburg P. H., Sakmann B. Structural determinants of ion flow through recombinant glutamate receptor channels. Science. 1991 Jun 21;252(5013):1715–1718. doi: 10.1126/science.1710829. [DOI] [PubMed] [Google Scholar]
- Weiss S., Kemp D. E., Bauce L., Tse F. W. Kainate receptors coupled to the evoked release of [3H]-gamma-aminobutyric acid from striatal neurons in primary culture: potentiation by lithium ions. Mol Pharmacol. 1990 Aug;38(2):229–236. [PubMed] [Google Scholar]
- Werner P., Voigt M., Keinänen K., Wisden W., Seeburg P. H. Cloning of a putative high-affinity kainate receptor expressed predominantly in hippocampal CA3 cells. Nature. 1991 Jun 27;351(6329):742–744. doi: 10.1038/351742a0. [DOI] [PubMed] [Google Scholar]
- Yoshimura M., Jessell T. Amino acid-mediated EPSPs at primary afferent synapses with substantia gelatinosa neurones in the rat spinal cord. J Physiol. 1990 Nov;430:315–335. doi: 10.1113/jphysiol.1990.sp018293. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Yuste R., Katz L. C. Control of postsynaptic Ca2+ influx in developing neocortex by excitatory and inhibitory neurotransmitters. Neuron. 1991 Mar;6(3):333–344. doi: 10.1016/0896-6273(91)90243-s. [DOI] [PubMed] [Google Scholar]