Recording and Analyzing Synaptic Currents and Synaptic Potentials

Laurence Trussell1

1 Oregon Health Sciences University, Portland, Oregon
Publication Name:  Current Protocols in Neuroscience
Unit Number:  Unit 6.10
DOI:  10.1002/0471142301.ns0610s07
Online Posting Date:  May, 2001
GO TO THE FULL TEXT: PDF or HTML at Wiley Online Library


Intracellular recording of synaptic currents (PSCs) under voltage clamp conditions provides the most accurate and direct means for measuring the earliest effects of neurotransmitters. With this tool, combined with pharmacological or ionic manipulations, one can obtain information about the type of transmitter used at a synapse, the dynamics of transmitterā€receptor interactions, the types and numbers of receptors activated, the effects of drugs on transmission, functional neural circuitry, and indications about the mechanisms of synaptic plasticity. Each synaptic current or potential is a reflection of many experimental variables: the ionic composition of the solutions, the temperature, the presence of pharmacological agents, the rate of synaptic stimulation, the history of stimulation, the variables of the recording system, as well as other factors unique to each preparation. Correct analysis of data requires all these parameters be considered. Both stimulusā€evoked and spontaneous synaptic events are covered in this unit since conclusions about synaptic and drug mechanisms are strongest when based upon recording of both types of activity. This unit outlines basic considerations for recording PSCs and PSPs in addition to guidelines for data analysis.

PDF or HTML at Wiley Online Library

Table of Contents

  • Recording and Analyzing Synaptic Currents and Synaptic Potentials
  • Strategic Planning
  • Basic Protocol 1: Recording Synaptic Events in Brain Slices
  • Commentary
  • Literature Cited
  • Figures
  • Tables
PDF or HTML at Wiley Online Library


Basic Protocol 1: Recording Synaptic Events in Brain Slices

  • Tissue slice maintained in chamber with standard Ringers solution (see units 6.4 & 6.5)
  • External and patch‐pipet solutions (see Critical Parameters)
  • Test compound (e.g., Research Biochemicals, Tocris Cookson)
  • Recording solution with selective ion‐channel blockers (see Commentary)
  • Electrophysiology setup for patch‐clamp (see Table 97.80.4711 and units 6.1, 6.2, & 6.6)
  • Tape recorders (VCR with PCM adapter, DAT drive, or audio recorder)
  • Patch pipets (see units 6.3, 6.6, & 6.7)
  • Stimulus pipets (see Critical Parameters)
  • Stimulus isolators (AMPI; distributed in the U.S. by Pacer Scientific or Grass Instruments)
  • Acquisition/analysis hardware and software: pCLAMP, AxoBasic, AxoGraph (Axon Instruments) or CDR (Strathclyde Software)
  • Plotting/curve‐fitting software: Origin 5.0 (Microcal Software) or Igor (WaveMetrics)
PDF or HTML at Wiley Online Library



Literature Cited

Literature Cited
   Ankri, N., Legendre, P., Faber, D.S., and Korn, H. 1994. Automatic detection of spontaneous synaptic responses in central neurons. J. Neurosci. Methods. 52:87‐100.
   Bekkers, J.M. and Stevens, C.F. 1991. Excitatory and inhibitory autaptic currents in isolated hippocampal neurons maintained in cell culture. Proc. Natl. Acad. Sci. U.S.A. 88:7834‐7838.
   Bekkers, J.M. and Stevens, C.F. 1992. Osmotic stimulation of presynaptic terminals. In Practical Electrophysiological Methods (H. Kettenman and R. Grantyn, eds.) pp. 150‐154. Wiley‐Liss, New York.
   Berry, M.S. and Pentreath, V.W. 1976. Criteria for distinguishing between monosynaptic and polysynaptic transmission. Brain Res. 105:1‐20.
   Borst, J.G. and Sakmann, B. 1996. Calcium influx and transmitter release in a fast CNS synapse. Nature 383:431‐434.
   Brown, T.H. and Johnston, D. 1983. Voltage clamp analysis of mossy fiber synaptic input to hippocampal neurons. J. Neurophysiol. 50:487‐507.
   Bruns, D. and Jahn, R. 1995. Real‐time measurement of transmitter release from single synaptic vesicles. Nature 377:62‐65.
   Cooke, I. and Lipkin, M. 1972. Cellular Neurophysiology: A Sourcebook. Holt, Rinehart, and Winston, New York.
   Covey, E., Kauer, J.A., and Cassaday, J.H. 1996. Whole‐cell patch‐clamp recording reveals subthreshold sound‐evoked postsynaptic currents in the inferior colliculus of awake bats. J. Neurosci. 16:3009‐3018.
   Dempster, J. 1993. Computer Analysis of Electrophysiological Signals. Academic Press, San Diego, Calif.
   Dodge, F.A., Miledi, R., and Rahamimoff, R. 1969. Strontium and quantal release of transmitter at the neuromuscular junction. J. Physiol. 200:267‐283.
   Edwards, F.A., Konnerth, A., and Sakmann, B. 1990. Quantal analysis of inhibitory synaptic transmission in the dentate gyrus of rat hippocampal slices: A patch clamp study. J. Physiol. 430:213‐249.
   Fatt, P. and Katz, B. 1952. Spontaneous subthreshold activity at motor nerve endings. J. Physiol. 117:109‐128.
   Goda, Y. and Stevens, C.F. 1994. Two components of transmitter release at a central synapse. Proc. Natl. Acad. Sci. U.S.A. 91:12942‐12946.
   Gyenes, M., Farrant, M., and Farb, D.H. 1988. “Run‐down” of γ‐aminobutyric acidA receptor function during whole‐cell recording: A possible role for phosphorylation. Mol Pharmacol. 34:719‐723.
   Hausser, M. and Roth, A. 1997. Estimating the time course of the excitatory synaptic conductance in neocortical pyramidal cells using a novel voltage jump method. J. Neurosci. 17:7606‐7625.
   Hestrin, S., Nicoll, R.A., Perkel, D.J., and Sah, P. 1990. Analysis of excitatory synaptic action in pyramidal cells using whole‐cell recording from rat hippocampal slices. J. Physiol. 422:203‐225.
   Hubbard, J.I., Llinas, R., and Quastel, D.M. 1969. Electrophysiological Analysis of Synaptic Transmission. Edward Arnold, London.
   Huettner, J.E. and Baughman, R.W. 1988. The pharmacology of synapses formed by identified corticocollicular neurons in primary cultures of rat visual cortex. J. Neurosci. 8:160‐175.
   Isaacson, J.S. and Walmsley, B. 1995. Counting quanta: Direct measurements of transmitter release at a central synapse. Neuron 15:875‐884.
   Katz, B. and Miledi, R. 1965. The effect of temperature on the synaptic delay at the neuromuscular junction. J. Physiol. 181:656‐670.
   Katz, L.C. and Dalva, M.B. 1994. Scanning laser photostimulation: A new approach for analysing brain circuits. J. Neurosci. Methods 54:205‐218.
   Korn, H., Sur, C., Charpier, S., Legendre, P., and Faber, D.S. 1994. The one‐vesicle hypothesis and multivesicular release. Adv.Second Messenger Phosphoprotein Res. 29:301‐322.
   Lichtman, J. and Frank, E. 1984. Physiological evidence for specificity of synaptic connections between individual sensory and motor neurons in the brachial spinal cord of the bullfrog. J. Neurosci. 4:1745‐1753.
   Liu, G. and Feldman, J.L. 1992. Quantal synaptic transmission in phrenic motor nucleus. J. Neurophysiol. 68:1468‐1471.
   Llano, I., Marty, A., Armstrong, C.M., and Konnerth, A. 1991. Synaptic‐ and agonist‐induced excitatory current of Purkinje cells in rat cerebellar slices. J. Physiol. 434:183‐213.
   MacDonald, J.F., Mody, I., and Salter, M.W. 1989. Regulation of N‐methyl‐D‐aspartate receptors revealed by intracellular dialysis of murine neurons in culture. J. Physiol. 414:17‐34.
   Magleby, K.L. and Miller, D.C. 1981. Is the quantum of transmitter release composed of subunits? A critical analysis in the mouse and frog. J. Physiol. 311:267‐287.
   Otis, T. and Trussell, L. 1996. Inhibition of transmitter release shortens the duration of the excitatory synaptic current at a calyceal synapse. J. Neurophysiol. In press.
   Otis, T.S., De Koninck, Y., and Mody, I. 1993. Characterization of synaptically elicited GABAB responses using patch‐clamp recordings in rat hippocampal slices. J. Physiol. 463:391‐407.
   Otis, T.S., Wu, Y.C., Trussell, L.O. 1996. Delayed clearance of transmitter and the role of glutamate transporters at synapses with multiple release sites. J. Neurosci. 16:1634‐1644.
   Role, L.W. and Fischbach, G.D. 1987. Changes in the number of chick ciliary ganglia neurons processes with time in cell culture. J. Cell. Biol. 104:363‐370.
   Sabatini, B.L. and Regehr, W.G. 1996. Timing of neurotransmission at fast synapses in the mammalian brain. Nature 384:170‐172.
   Silver, R.A., Cull‐Candy, S.G., and Takahashi, T. 1996. Non‐NMDA glutamate receptor occupancy and open probability at a rat cerebellar synapse with single and multiple release sites. J. Physiol. 494:231‐250.
   Spruston, N., Jaffe, D.B., Williams, S.H., and Johnston, D.V. 1993. Voltage‐ and space‐clamp errors associated with the measurement of electrotonically remote synaptic events. J. Neurophysiol. 70:781‐802.
   Stevens, C.F. and Wang, Y. 1995. Facilitation and depression at single central synapses. Neuron 14:795‐802.
   Takahashi, M., Kovalchuk, Y., and Attwell, D. 1995. Pre‐ and postsynaptic determinants of EPSC waveform at cerebellar climbing fiber and parallel fiber to Purkinje cell synapses. J. Neurosci. 15:5693‐5702.
   Tang, C.M., Margulis, M., Shi, Q.‐Y., and Fielding, A. 1994. Saturation of postsynaptic glutamate receptors after quantal release of trnansmitter. Neuron 13:1385‐1393.
   Trussell, L.O. and Jackson, M.B. 1987. Dependence of an adenosine‐activated potassium current on a GTP‐binding protein in mammalian central neurons. J. Neurosci. 7:3306‐3316.
   Van der Kloot, W. 1996. Statistics for studying quanta at synapses: Resampling and confidence limits on histograms. J. Neurosci. Methods 65:151‐155.
   Vincent, P. and Marty, A. 1996. Fluctuations of inhibitory postsynaptic currents in Purkinje cells from rat cerebellar slices. J. Physiol. 494:183‐199.
   von Gersdorff, H. and Matthews, G. 1994. Dynamics of synaptic vesicle fusion and membrane retrieval in synaptic terminals. Nature 367:735‐739.
   Zhang, S. and Oertel, D. 1993. Tuberculoventral cells of the dorsal cochlear nucleus of mice: Intracellular recordings in slices. J. Neurophysiol. 69:1409‐1421.
   Zhang, S. and Trussell, L.O. 1994a. A characterization of excitatory postsynaptic potentials in the avian nucleus magnocellularis. J. Neurophysiol. 72:705‐718.
   Zhang, S. and Trussell, L.O. 1994b. Voltage clamp analysis of excitatory synaptic transmission in the avian nucleus magnocellularis. J. Physiol. 480:123‐136.
PDF or HTML at Wiley Online Library