Summary
Long-term potentiation is a synaptic mechanism thought to be involved in learning and memory. Long-term depression (LTD), an activity-dependent decrease in synaptic efficacy, may be an equally important mechanism that permits neural networks to store information more effectively. Two forms of LTD have been identified in the mammalian central nervous system, which are induced by the synaptic activation of N-methyl-d-aspartate (NMDA) and metabotropic glutamate (mGlu) receptors, respectively. Whereas the expression mechanisms of NMDA receptor-dependent LTD have been demonstrated to be postsynaptic, those of mGlu receptor-dependent LTD have not been clearly identified. In order to address this issue, a variety of different electrophysiological methods have been used. A very elegant way to realize this experimental approach is provided by the development of photolytic application of glutamate, which allows the temporally and spatially highly specific activation of any neuron or any part of the neuron. By means of simultaneous application of electrical and photolytic stimulation techniques, it has been demonstrated that mGlu receptor-induced LTD is compatible with a presynaptic mechanism of expression.
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References
Bear, M.F. and W.C. Abraham. (1996) Long-term depression in hippocampus. Ann Rev Neurosci. 19, 437–462.
Palmer, M.J., A.J. Irving, G.R. Seabrook, D.E. Jane, and G.L. Collingridge. (1997) The group I mGlu receptor agonist DHPG induces a novel form of LTD in the CA1 region of the hippocampus. Neuropharmacology 36, 1517–1532.
Fitzjohn, S.M., A.E. Kingston, D. Lodge, and G.L. Collingridge. (1999) DHPG-induced LTD in area CA1 of juvenile rat hippocampus; characterisation and sensitivity to novel mGlu receptor antagonists. Neuropharmacology 38, 1577–1583.
Camodeca, N., N.A. Breakwell, M.J. Rowan, and R. Anwyl. (1999) Induction of LTD by activation of group I mGluR in the dentate gyrus in vitro. Neuropharmacology 38, 1597–1606.
Huber, K.M., J.C. Roder, and M.F. Bear. (2001) Chemical induction of mGluR5- and protein synthesis-dependent long-term depression in hippocampal area CA1. J Neurophysiol. 86, 321–325.
Fitzjohn, S.M., R.A. Morton, F. Kuenzi, T.W. Rosahl, M. Shearman, H. Lewis, D. Smith, D.S. Reynolds, C.H. Davies, G.L. Collingridge, and G.R. Seabrook. (2001) Age-related impairment of synaptic transmission but normal long-term potentiation in transgenic mice that overexpress the human APP695SWE mutant form of amyloid precursor protein. J Neurosci. 21, 4691–4698.
Kleppisch, T., V. Voigt, R. Allmann, and S. Offermanns. (2001) G(alpha) q-deficient mice lack metabotropic glutamate receptor-dependent long-term depression but show normal long-term potentiation in the hippocampal CA1 region. J Neurosci. 21, 4943–4948.
Schnabel, R., I.C. Kilpatrick, and G.L. Collingridge. (2001) Protein phosphatase inhibitors facilitate DHPG-induced LTD in the CA1 region of the hippocampus. Br J Pharmacol. 132, 1095–1101.
Snyder, E.M., B.D. Philpot, K.M. Huber, X. Dong, J.R. Fallon, and M.F. Bear. (2001) Internalization of ionotropic glutamate receptors in response to mGluR activation. Nat Neurosci. 4, 1079–1085.
Xiao, M.Y., Q. Zhou, and R.A. Nicoll. (2001) Metabotropic glutamate receptor activation causes a rapid redistribution of AMPA receptors. Neuropharmacology. 41, 664–671.
Watabe, A.M., H.J. Carlisle, and T.J. O’Dell. (2002) Postsynaptic induction and presynaptic expression of group 1 mGluR-dependent LTD in the hippocampal CA1 region. J Neurophysiol. 87(3):1395–1403.
Fitzjohn, S.M., M.J. Palmer, J.E.R. May, A. Neeson, S.A.C. Morris, and G.L. Collingridge. (2001) A characterisation of long-term depression induced by metabotropic glutamate receptor activation in the rat hippocampus in vitro. J Physiol (Lond). 537(2):421–430.
Wieboldt, R., K.R. Gee, L. Niu, D. Ramesh, B.K. Carpenter, and G.P. Hess. (1994) Photolabile precursors of glutamate: synthesis, photochemical properties, and activation of glutamate receptors on a microsecond time scale. Proc Natl Acad Sci USA. 91, 8752–8756.
Eder, M., W. Zieglgansberger, and H.U. Dodt. (2002) Neocortical long-term potentiation and long-term depression: site of expression investigated by infrared-guided laser stimulation. J Neurosci. 22, 7558–7568.
Schubert, D., J.F. Staiger, N. Cho, R. Kotter, K. Zilles, and H.J. Luhmann. (2001) Layer-specific intracolumnar and transcolumnar functional connectivity of layer V pyramidal cells in rat barrel cortex. J Neurosci. 21, 3580–3592.
Dodt, H.U., M. Eder, A. Frick, and W. Zieglgansberger. (1999) Precisely localized LTD in the neocortex revealed by infrared-guided laser stimulation. Science. 286(5437):110–113.
Dodt, H.U. and W. Zieglgansberger. (1994) Infrared videomicroscopy: a new look at neuronal structure and function [Review] [43 refs]. Trends Neurosci. 17, 453–458.
Dodt, H.U., M. Eder, A. Schierloh, and W. Zieglgansberger. (2002) Infrared-guided laser stimulation of neurons in brain slices. Sci STKE. 2002, PL2.
Eder, M., W. Zieglgansberger, and H.U. Dodt. (2004) Shining light on neurons–elucidation of neuronal functions by photostimulation. Rev Neurosci. 15, 167–183.
Rammes, G., M. Palmer, M. Eder, H.U. Dodt, W. Zieglgansberger, and G.L. Collingridge. (2003) Activation of mGlu receptors induces LTD without affecting postsynaptic sensitivity of CA1 neurons in rat hippocampal slices. J Physiol. 546, 455–460.
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Rammes, G., Eder, M., Zieglgänsberger, W., Dodt, HU. (2007). Infrared-Guided Laser Stimulation as a Tool for Elucidating the Synaptic Site of Expression of Long-Term Synaptic Plasticity. In: Molnar, P., Hickman, J.J. (eds) Patch-Clamp Methods and Protocols. Methods in Molecular Biology™, vol 403. Humana Press. https://doi.org/10.1007/978-1-59745-529-9_7
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DOI: https://doi.org/10.1007/978-1-59745-529-9_7
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