Is Conditioning Supported by Modulation of an Outward Current in Pyramidal Cells of the Motor Cortex of Cats?

  • Charles D. Woody


Layer V pyramidal cells of the motor cortex of cats are necessary for short-latency blink conditioning (Woody et al., 1974). Increases in their excitability support production of this learned motor response (Woody et al., 1970; Woody and Engel, 1972; Woody and Black-Cleworth, 1973; Brons and Woody, 1980). Early evidence suggested (Woody and Black-Cleworth, 1973) that a decreased postsynaptic conductance might support the excitability increase. Further studies indicate that the input resistance (R m) of these cells is increased by acetylcholine (ACh), cGMP, and cGMP-dependent protein kinase (cGPK) but not by cAMP or Ca2+ (Woody et al., 1978, 1986; Swartz and Woody, 1979, 1984; Wallis et al., 1982; Bartfai et al., 1985; Woody and Gruen, 1986b). The increase in R m is persistent when depolarization-induced cell discharge accompanies application of ACh, cGMP, or cGPK. Recent studies using single-electrode voltage-clamp techniques in vivo now provide direct evidence that ACh and cGPK decrease a net outward current in these cells (Woody and Gruen, 1986a). We suggest that a persistent decrease in this current may mediate the excitability increase that supports short-latency conditioned blinking.


Motor Cortex Outward Current Input Resistance Dendritic Tree Conditioned Eyeblink 
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Copyright information

© Springer Science+Business Media New York 1988

Authors and Affiliations

  • Charles D. Woody
    • 1
  1. 1.Mental Retardation Research CenterBrain Research Institute, University of California at Los AngelesLos AngelesUSA

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