Studies on Extracellular Potentials Generated by Synaptic Activity on Single Cat Motor Cortex Neurons

  • W. Raabe
  • H. D. Lux


When intracellular recordings from cortical neurons became available it was obvious to most workers in this field that a relationship exists especially between the postsynaptic potentials and the potential recorded from the cortical surface (Kandel and Spencer 1961, Li and Chou 1962, Lux and Klee 1962, Creutzfeldt et al. 1964, Pollen 1964, Purpura et al. 1964, Jasper and Stefanis 1965) in accord-ance with an earlier hypothesis of Eccles (1951). In the neocortex, the postsynaptic activity of pyramidal tract (PT) cells was assumed to govern the generation of the electrocorticogram and special consideration in this respect was given to the localization of excitatory and inhibitory synapses on the nerve cell soma and apical dendrite (Eccles 1951, Creutzfeldt et al. 1966). In a more recent study by Humphrey (1968), evidence was presented for a causal relationship between the postsynaptic effects of synchronous recurrent activity of PT cells with the antidromically evoked surface potential. A PT cell model was proposed which rather effectively combined electrophysiological and morphological data. It allowed a quantitative interpretation of this evoked potential based on synaptic activity on single PT neurons. For a check of the model it was thought worthwhile to test experimentally to what amount synaptic currents contribute to the potential field in the extracellular adjacent surround of this neuron.


Pyramidal Tract Synaptic Activity Cortical Surface Apical Dendrite Extracellular Potential 
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Copyright information

© Springer-Verlag/Wien 1972

Authors and Affiliations

  • W. Raabe
    • 1
  • H. D. Lux
    • 1
  1. 1.Max-Planck-Institut für PsychiatrieMünchenGermany

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