Chinese Science Bulletin

, Volume 48, Issue 5, pp 417–423 | Cite as

Modulation of presynaptic nAChRs on postsynaptic GABA receptor in optic tectum of juvenileXenopus



Using the blind patch-clamp technique with the whole-cell mode, we have studied the modulation of presynaptic receptor on postsynaptic γ-aminobutyric acid (GABA) receptor measuring miniature inhibitory postsynaptic currents (mIPSCs) in optic tectum ofXenopus during critical peroid. It was demonstrated that compared with mature neurons, mIPSCs recorded from immature neurons had smaller amplitude and longer decay time. mIPSCs are mediated by GABAa receptor. The nicotinic acetylcholine receptor agonists (carbachol, cytisine, nicotine, DMPP and so on) could increase the frequency of mIPSCs. The enhancement of mIPSCs frequency induced by nAChR agonists was calcium-dependent. However, the choline, a product of hydrolyzed acetylcholine, could not increase the frequency of mIPSCs. DH-β-E, a competitive antagonist of nAChR, blocked the increase of mIPSCs frequency induced by carbachol. Mecamyllamine, an α3β4 subtype of nAChR antagonist, also blocked the carbachol-induced enhancement of mIPSCs. On the other hand, MLA, α7 subtype of nAChR antagonist, had no effect on it. Thus, it seems that nAChR could presynaptically modulate the mIPSCs and α3β4 subtype of nAChR might be involved. But α7 nAChR subtype of nAChR would not be involved. The modulation is calciumdependent. Meanwhile, we found that Ca2+-free solution could elicit giant PSCs. The frequency of mIPSCs also is related with the level of HP.


optic tectum brain slice critical period 


mIPSCs patch clamp nAChR 


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  1. 1.
    Hickmott, P. W., Paton, M. C., The contribution of NMDA, non-NMDA, and GABA receptors to postsynaptic responses in neurons of the optic tectum, J. Neurosci., 1993, 13(100): 4339–4353.Google Scholar
  2. 2.
    Barker, J. L., Behar, T., Li, Y. X. et al., GABAergic cells and signals in CNS development, Perspect. Dev. Neuribiol., 1998, 5: 305–322.Google Scholar
  3. 3.
    Lunmann, H. J., Prince, D. A., Postnatal maturation of the GABAergic system in rat neocortex, J. Neurophysiol., 1991, 65(2): 237–263.Google Scholar
  4. 4.
    Wen, X. H., Tsai, H. J., Modulation of presynaptic nAChR on mPSC of optic tectem in adultXenopus frogs, Chin. J. Neurosci. (in Chinese), 2001, 17(3): 209–213.Google Scholar
  5. 5.
    Clarke, P. B. S., Nicotinic receptors in mammalian brain: localization and relation to cholinergic innervation, Prog. Brain. Res., 1993, 98: 77–83.CrossRefGoogle Scholar
  6. 6.
    Udin, S. B., Grant, S., Plasticity in the tectum ofXenopus Laevis: binocular maps, Prog. Neurobiol., 1999, 59: 81–106.CrossRefGoogle Scholar
  7. 7.
    Ricciuti, A., Gruberg, E. R., Nucleus isthmi provide most tectal choline acetyltransferase in the frog Rana pipiens, Brain. Res., 1985, 341: 399–402.CrossRefGoogle Scholar
  8. 8.
    Titmus, M. J., Tsai, H. J., Udin, S. B., Effects of choline and other nicotinic agonists on the tectum of juvenile and adult Xenopus frogs: Apatch-clamp study, Neuroscience, 1999, 91: 753–769.CrossRefGoogle Scholar
  9. 9.
    Blanton, M. G., Lo Turco, J. J., Kriegstein, A. R., Whole cell recording from neurons in slices of reptilian and mammalian cerebral cortex, J. Neurosci. Meth., 1989, 30: 203–210.CrossRefGoogle Scholar
  10. 10.
    Llano, I., Gerschenfeld, H. M., Inhibitory synaptic currents in stellate cells of rat cerebellar slices, J. Physiol., 1993, 468: 177–200.Google Scholar
  11. 11.
    Guo, J. Z., Tredway, T. L., Chiappinelli, V. A., Glutamate and GABA release are enhanced by different subtypes of presynaptic nicotinic receptors in the lateral geniculate nucleus, J. Neurosci., 1998, 18(6): 1963–1969.Google Scholar
  12. 12.
    Liu, Y. B., Peter, A. L., Joseph, F., Developmental changes in membrane properties and postsynaptic currents of granule cells in rat dentate gyrus, J. Neurophysio., 1996, 36(2): 1074–1088.Google Scholar
  13. 13.
    Cherubini, E., Conti, F., Generating diversity at GABAergic synapses, TINS, 2001, 24(3): 155–162.Google Scholar
  14. 14.
    Lester, R. A. J., Tahr, C. E., NMDA channel behavior depends on agonist affinity, J. Neurosci., 1992: 12: 635–643.Google Scholar
  15. 15.
    Wu, J. Y., Malinow, R., Cline, H. T., Maturation of a central glutamatergic synapse, Science, 1996, 274(8): 972–976.CrossRefGoogle Scholar
  16. 16.
    Parnas, H., Segel, L., Dudel, J. et al., Autoreceptors, membrane potential and the regulation of transmitter release, TINS, 2000, 23(2): 60–68.Google Scholar
  17. 17.
    Llano, I., Gonzalez, J., Caputo, F. et al., Presynaptic calcium stores underlie large-amplitude minazture IPSCs and spontaneous calcium transients, Nat. Neurosci., 2000, 3(12): 1256–1265.CrossRefGoogle Scholar
  18. 18.
    Cheng, H., Lederer, W. J., Cannell, M. B., Calcium sparks: elementary events underlying excitation-contraction coupling in heart muscle, Science, 1993, 262(29): 740–744.CrossRefGoogle Scholar

Copyright information

© Science in China Press 2003

Authors and Affiliations

  1. 1.First HospitalPeking UniversityBeijingChina

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