Abstract
Patch-clamp recording requires direct accessibility of the cell membrane to patch pipettes and allows the investigation of ion channel properties and functions in specific cellular compartments. The cell body and relatively thick dendrites are the most accessible compartments of a neuron, due to their large diameters and therefore great membrane surface areas. However, axons are normally inaccessible to patch pipettes because of their thin structure; thus studies of axon physiology have long been hampered by the lack of axon recording methods. Recently, a new method of patch-clamp recording has been developed, enabling direct and tight-seal recording from cortical axons. These recordings are performed at the enlarged structure (axonal bleb) formed at the cut end of an axon after slicing procedures. This method has facilitated studies of the mechanisms underlying the generation and propagation of the main output signal, the action potential, and led to the finding that cortical neurons communicate not only in action potential-mediated digital mode but also in membrane potential-dependent analog mode.
Keywords: axon, patch-clamp recording, ion channel, action potential
References
- [1].Hu W., Tian C., Li T., Yang M., Hou H., Shu Y. Distinct contributions of Na(v)1.6 and Na(v)1.2 in action potential initiation and back-propagation. Nat Neurosci. 2009;12:996–1002. doi: 10.1038/nn.2359. [DOI] [PubMed] [Google Scholar]
- [2].Shu Y., Duque A., Yu Y., Haider B., McCormick D.A. Properties of action-potential initiation in neocortical pyramidal cells: evidence from whole cell axon recordings. J Neurophysiol. 2007;97:746–760. doi: 10.1152/jn.00922.2006. [DOI] [PubMed] [Google Scholar]
- [3].Shu Y., Hasenstaub A., Duque A., Yu Y., McCormick D.A. Modulation of intracortical synaptic potentials by presynaptic somatic membrane potential. Nature. 2006;441:761–765. doi: 10.1038/nature04720. [DOI] [PubMed] [Google Scholar]
- [4].Shu Y., Yu Y., Yang J., McCormick D.A. Selective control of cortical axonal spikes by a slowly inactivating K+ current. Proc Natl Acad Sci U S A. 2007;104:11453–11458. doi: 10.1073/pnas.0702041104. [DOI] [PMC free article] [PubMed] [Google Scholar]
- [5].Debanne D., Campanac E., Bialowas A., Carlier E., Alcaraz G. Axon physiology. Physiol Rev. 2011;91:555–602. doi: 10.1152/physrev.00048.2009. [DOI] [PubMed] [Google Scholar]
- [6].Kole M.H., Stuart G.J. Signal processing in the axon initial segment. Neuron. 2012;73:235–247. doi: 10.1016/j.neuron.2012.01.007. [DOI] [PubMed] [Google Scholar]
- [7].Rasband M.N. The axon initial segment and the maintenance of neuronal polarity. Nat Rev Neurosci. 2010;11:552–562. doi: 10.1038/nrn2852. [DOI] [PubMed] [Google Scholar]
- [8].Cole K.S. Membranes, Ions and Impulses. Berkeley: University of California Press; 1968. [Google Scholar]
- [9].Hodgkin A.L., Huxley A.F., Katz B. Measurement of current-voltage relations in the membrane of the giant axon of Loligo. J Physiol. 1952;116:424–448. doi: 10.1113/jphysiol.1952.sp004716. [DOI] [PMC free article] [PubMed] [Google Scholar]
- [10].Marmont G. Studies on the axon membrane; a new method. J Cell Physiol. 1949;34:351–382. doi: 10.1002/jcp.1030340303. [DOI] [PubMed] [Google Scholar]
- [11].Young J.Z. The giant nerve fibres and epistellar body of cephalopods. Q J Microsc Sci. 1936;78:367–386. [Google Scholar]
- [12].Hodgkin A.L., Huxley A.F. A quantitative description of membrane current and its application to conduction and excitation in nerve. J Physiol. 1952;117:500–544. doi: 10.1113/jphysiol.1952.sp004764. [DOI] [PMC free article] [PubMed] [Google Scholar]
- [13].Neher E., Sakmann B. Single-channel currents recorded from membrane of denervated frog muscle fibres. Nature. 1976;260:799–802. doi: 10.1038/260799a0. [DOI] [PubMed] [Google Scholar]
- [14].Borst J.G., Helmchen F., Sakmann B. Pre- and postsynaptic whole-cell recordings in the medial nucleus of the trapezoid body of the rat. J Physiol. 1995;489(Pt3):825–840. doi: 10.1113/jphysiol.1995.sp021095. [DOI] [PMC free article] [PubMed] [Google Scholar]
- [15].Forsythe I.D. Direct patch recording from identified presynaptic terminals mediating glutamatergic EPSCs in the rat CNS, in vitro. J Physiol. 1994;479(Pt3):381–387. doi: 10.1113/jphysiol.1994.sp020303. [DOI] [PMC free article] [PubMed] [Google Scholar]
- [16].Schneggenburger R., Meyer A.C., Neher E. Released fraction and total size of a pool of immediately available transmitter quanta at a calyx synapse. Neuron. 1999;23:399–409. doi: 10.1016/S0896-6273(00)80789-8. [DOI] [PubMed] [Google Scholar]
- [17].Geiger J.R., Jonas P. Dynamic control of presynaptic Ca2+ inflow by fast-inactivating K+ channels in hippocampal mossy fiber boutons. Neuron. 2000;28:927–939. doi: 10.1016/S0896-6273(00)00164-1. [DOI] [PubMed] [Google Scholar]
- [18].Colbert C.M., Pan E. Ion channel properties underlying axonal action potential initiation in pyramidal neurons. Nat Neurosci. 2002;5:533–538. doi: 10.1038/nn0602-857. [DOI] [PubMed] [Google Scholar]
- [19].Kole M.H., Ilschner S.U., Kampa B.M., Williams S.R., Ruben P.C., Stuart G.J. Action potential generation requires a high sodium channel density in the axon initial segment. Nat Neurosci. 2008;11:178–186. doi: 10.1038/nn2040. [DOI] [PubMed] [Google Scholar]
- [20].Stuart G., Schiller J., Sakmann B. Action potential initiation and propagation in rat neocortical pyramidal neurons. J Physiol. 1997;505(Pt3):617–632. doi: 10.1111/j.1469-7793.1997.617ba.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- [21].Stuart G., Spruston N., Sakmann B., Hausser M. Action potential initiation and backpropagation in neurons of the mammalian CNS. Trends Neurosci. 1997;20:125–131. doi: 10.1016/S0166-2236(96)10075-8. [DOI] [PubMed] [Google Scholar]
- [22].Schneggenburger R., Forsythe I.D. The calyx of Held. Cell Tissue Res. 2006;326:311–337. doi: 10.1007/s00441-006-0272-7. [DOI] [PubMed] [Google Scholar]
- [23].Acsady L., Kamondi A., Sik A., Freund T., Buzsaki G. GABAergic cells are the major postsynaptic targets of mossy fibers in the rat hippocampus. J Neurosci. 1998;18:3386–3403. doi: 10.1523/JNEUROSCI.18-09-03386.1998. [DOI] [PMC free article] [PubMed] [Google Scholar]
- [24].Amaral D.G., Dent J.A. Development of the mossy fibers of the dentate gyrus: I. A light and electron microscopic study of the mossy fibers and their expansions. J Comp Neurol. 1981;195:51–86. doi: 10.1002/cne.901950106. [DOI] [PubMed] [Google Scholar]
- [25].Blackstad T.W., Kjaerheim A. Special axo-dendritic synapses in the hippocampal cortex: electron and light microscopic studies on the layer of mossy fibers. J Comp Neurol. 1961;117:133–159. doi: 10.1002/cne.901170202. [DOI] [PubMed] [Google Scholar]
- [26].Alle H., Geiger J.R. Combined analog and action potential coding in hippocampal mossy fibers. Science. 2006;311:1290–1293. doi: 10.1126/science.1119055. [DOI] [PubMed] [Google Scholar]
- [27].Alle H., Roth A., Geiger J.R. Energy-efficient action potentials in hippocampal mossy fibers. Science. 2009;325:1405–1408. doi: 10.1126/science.1174331. [DOI] [PubMed] [Google Scholar]
- [28].Bischofberger J., Engel D., Li L., Geiger J.R., Jonas P. Patch-clamp recording from mossy fiber terminals in hippocampal slices. Nat Protoc. 2006;1:2075–2081. doi: 10.1038/nprot.2006.312. [DOI] [PubMed] [Google Scholar]
- [29].Ramon y Cajal S. Degeneration and Regeneration of the Nervous System. New York: Oxford University Press, American Branch; 1928. [Google Scholar]
- [30].Erturk A., Hellal F., Enes J., Bradke F. Disorganized microtubules underlie the formation of retraction bulbs and the failure of axonal regeneration. J Neurosci. 2007;27:9169–9180. doi: 10.1523/JNEUROSCI.0612-07.2007. [DOI] [PMC free article] [PubMed] [Google Scholar]
- [31].Hill C.E., Beattie M.S., Bresnahan J.C. Degeneration and sprouting of identified descending supraspinal axons after contusive spinal cord injury in the rat. Exp Neurol. 2001;171:153–169. doi: 10.1006/exnr.2001.7734. [DOI] [PubMed] [Google Scholar]
- [32].Li Y., Raisman G. Sprouts from cut corticospinal axons persist in the presence of astrocytic scarring in long-term lesions of the adult rat spinal cord. Exp Neurol. 1995;134:102–111. doi: 10.1006/exnr.1995.1041. [DOI] [PubMed] [Google Scholar]
- [33].McCormick D.A., Shu Y., Yu Y. Neurophysiology: Hodgkin and Huxley model — still standing? Nature. 2007;445:E1–2. doi: 10.1038/nature05523. [DOI] [PubMed] [Google Scholar]
- [34].Khaliq Z.M., Raman I.M. Axonal propagation of simple and complex spikes in cerebellar Purkinje neurons. J Neurosci. 2005;25:454–463. doi: 10.1523/JNEUROSCI.3045-04.2005. [DOI] [PMC free article] [PubMed] [Google Scholar]
- [35].Monsivais P., Clark B.A., Roth A., Hausser M. Determinants of action potential propagation in cerebellar Purkinje cell axons. J Neurosci. 2005;25:464–472. doi: 10.1523/JNEUROSCI.3871-04.2005. [DOI] [PMC free article] [PubMed] [Google Scholar]
- [36].Storm J.F. Temporal integration by a slowly inactivating K+ current in hippocampal neurons. Nature. 1988;336:379–381. doi: 10.1038/336379a0. [DOI] [PubMed] [Google Scholar]
- [37].Kole M.H., Letzkus J.J., Stuart G.J. Axon initial segment Kv1 channels control axonal action potential waveform and synaptic efficacy. Neuron. 2007;55:633–647. doi: 10.1016/j.neuron.2007.07.031. [DOI] [PubMed] [Google Scholar]
- [38].Zhu J., Jiang M., Yang M., Hou H., Shu Y. Membrane potential-dependent modulation of recurrent inhibition in rat neocortex. PLoS Biol. 2011;9:e1001032. doi: 10.1371/journal.pbio.1001032. [DOI] [PMC free article] [PubMed] [Google Scholar]
- [39].Palmer L.M., Stuart G.J. Site of action potential initiation in layer 5 pyramidal neurons. J Neurosci. 2006;26:1854–1863. doi: 10.1523/JNEUROSCI.4812-05.2006. [DOI] [PMC free article] [PubMed] [Google Scholar]
- [40].Popovic M.A., Foust A.J., McCormick D.A., Zecevic D. The spatiotemporal characteristics of action potential initiation in layer 5 pyramidal neurons: a voltage imaging study. J Physiol. 2011;589:4167–4187. doi: 10.1113/jphysiol.2011.209015. [DOI] [PMC free article] [PubMed] [Google Scholar]
- [41].Kim S., Guzman S.J., Hu H., Jonas P. Active dendrites support efficient initiation of dendritic spikes in hippocampal CA3 pyramidal neurons. Nat Neurosci. 2012;15:600–606. doi: 10.1038/nn.3060. [DOI] [PMC free article] [PubMed] [Google Scholar]
- [42].Atherton J.F., Wokosin D.L., Ramanathan S., Bevan M.D. Autonomous initiation and propagation of action potentials in neurons of the subthalamic nucleus. J Physiol. 2008;586:5679–5700. doi: 10.1113/jphysiol.2008.155861. [DOI] [PMC free article] [PubMed] [Google Scholar]
- [43].Schmidt-Hieber C., Jonas P., Bischofberger J. Action potential initiation and propagation in hippocampal mossy fibre axons. J Physiol. 2008;586:1849–1857. doi: 10.1113/jphysiol.2007.150151. [DOI] [PMC free article] [PubMed] [Google Scholar]
- [44].Chen N., Yu J., Qian H., Ge R., Wang J.H. Axons amplify somatic incomplete spikes into uniform amplitudes in mouse cortical pyramidal neurons. PLoS One. 2010;5:e11868. doi: 10.1371/journal.pone.0011868. [DOI] [PMC free article] [PubMed] [Google Scholar]
- [45].Dodge F.A., Jr, Cooley J.W. Action potential of the motoneuron. IBM J Res Dev. 1973;17:219–229. doi: 10.1147/rd.173.0219. [DOI] [Google Scholar]
- [46].Lorincz A., Nusser Z. Cell-type-dependent molecular composition of the axon initial segment. J Neurosci. 2008;28:14329–14340. doi: 10.1523/JNEUROSCI.4833-08.2008. [DOI] [PMC free article] [PubMed] [Google Scholar]
- [47].Mainen Z.F., Joerges J., Huguenard J.R., Sejnowski T.J. A model of spike initiation in neocortical pyramidal neurons. Neuron. 1995;15:1427–1439. doi: 10.1016/0896-6273(95)90020-9. [DOI] [PubMed] [Google Scholar]
- [48].Moore J.W., Stockbridge N., Westerfield M. On the site of impulse initiation in a neurone. J Physiol. 1983;336:301–311. doi: 10.1113/jphysiol.1983.sp014582. [DOI] [PMC free article] [PubMed] [Google Scholar]
- [49].Rapp M., Yarom Y., Segev I. Modeling back propagating action potential in weakly excitable dendrites of neocortical pyramidal cells. Proc Natl Acad Sci U S A. 1996;93:11985–11990. doi: 10.1073/pnas.93.21.11985. [DOI] [PMC free article] [PubMed] [Google Scholar]
- [50].Schmidt-Hieber C., Bischofberger J. Fast sodium channel gating supports localized and efficient axonal action potential initiation. J Neurosci. 2010;30:10233–10242. doi: 10.1523/JNEUROSCI.6335-09.2010. [DOI] [PMC free article] [PubMed] [Google Scholar]
- [51].Grubb M.S., Shu Y., Kuba H., Rasband M.N., Wimmer V.C., Bender K.J. Short- and long-term plasticity at the axon initial segment. J Neurosci. 2011;31:16049–16055. doi: 10.1523/JNEUROSCI.4064-11.2011. [DOI] [PMC free article] [PubMed] [Google Scholar]
- [52].Arellano J.I., DeFelipe J., Munoz A. PSA-NCAM immunoreactivity in chandelier cell axon terminals of the human temporal cortex. Cereb Cortex. 2002;12:617–624. doi: 10.1093/cercor/12.6.617. [DOI] [PubMed] [Google Scholar]
- [53].DeFelipe J., Arellano J.I., Gomez A., Azmitia E.C., Munoz A. Pyramidal cell axons show a local specialization for GABA and 5-HT inputs in monkey and human cerebral cortex. J Comp Neurol. 2001;433:148–155. doi: 10.1002/cne.1132. [DOI] [PubMed] [Google Scholar]
- [54].Kullmann D.M., Ruiz A., Rusakov D.M., Scott R., Semyanov A., Walker M.C. Presynaptic, extrasynaptic and axonal GABAA receptors in the CNS: where and why? Prog Biophys Mol Biol. 2005;87:33–46. doi: 10.1016/j.pbiomolbio.2004.06.003. [DOI] [PMC free article] [PubMed] [Google Scholar]
- [55].Pugh J.R., Jahr C.E. Axonal GABAA receptors increase cerebellar granule cell excitability and synaptic activity. J Neurosci. 2011;31:565–574. doi: 10.1523/JNEUROSCI.4506-10.2011. [DOI] [PMC free article] [PubMed] [Google Scholar]
- [56].Christie J.M., Jahr C.E. Selective expression of ligand-gated ion channels in L5 pyramidal cell axons. J Neurosci. 2009;29:11441–11450. doi: 10.1523/JNEUROSCI.2387-09.2009. [DOI] [PMC free article] [PubMed] [Google Scholar]
- [57].Sasaki T., Matsuki N., Ikegaya Y. Action-potential modulation during axonal conduction. Science. 2011;331:599–601. doi: 10.1126/science.1197598. [DOI] [PubMed] [Google Scholar]
