Cortical Commands in Active Touch

  1. Derek J. Chadwick,
  2. Mathew Diamond Organizer and
  3. Jamie Goode
  1. Michael Brecht

Published Online: 7 OCT 2008

DOI: 10.1002/9780470034989.ch4

Percept, Decision, Action: Bridging the Gaps: Novartis Foundation Symposium 270

Percept, Decision, Action: Bridging the Gaps: Novartis Foundation Symposium 270

How to Cite

Brecht, M. (2006) Cortical Commands in Active Touch, in Percept, Decision, Action: Bridging the Gaps: Novartis Foundation Symposium 270 (eds D. J. Chadwick, M. Diamond and J. Goode), John Wiley & Sons, Ltd, Chichester, UK. doi: 10.1002/9780470034989.ch4

Author Information

  1. Erasmus MC, University Medical Center Rotterdam, Department of Neuroscience, Dr. Molewaterplein 50, 3015 Dr Rotterdam, The Netherlands

Publication History

  1. Published Online: 7 OCT 2008
  2. Published Print: 13 JAN 2006

Book Series:

  1. Novartis Foundation Symposia

Book Series Editors:

  1. Novartis Foundation

ISBN Information

Print ISBN: 9780470012338

Online ISBN: 9780470034989

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Keywords:

  • cortical commands;
  • cortical activity and cortical processing modes;
  • cortical synaptic transmission;
  • excitatory postsynaptic potentials (EPSPs);
  • peri-stimulus time histogram (PSTH) of whisking

Summary

The neocortex is an enormous network of extensively interconnected neurons. It has become clear that the computations performed by individual cortical neurons will critically depend on the quantitative composition of cortical activity. Here we discuss quantitative aspects of cortical activity and modes of cortical processing in the context of rodent active touch. Through in vivo whole-cell recordings one observes widespread subthreshold and very sparse evoked action potential (AP) activity in the somatosensory cortex both for passive whisker deflection in anaesthetized animals and during active whisker movements in awake animals. Neurons of the somatosensory cortex become either suppressed during whisking or activated by an efference copy of whisker movement signal that depolarize cells at certain phases of the whisking cycle. To probe the read out of cortical motor commands we applied intracellular stimulation in rat whisker motor cortex. We find that APs in individual cortical neurons can evoke long sequences of small whisker movements. The capacity of an individual neuron to evoke movements is most astonishing given the large number of neurons in whisker motor cortex. Thus, few cortical APs may suffice to control motor behaviour and such APs can be translated into action with the utmost precision. We conclude that there is very widespread subthreshold cortical activity and very sparse, highly specific cortical AP activity.