title: Identification of principal components in cortical evoked potentials by brief surface cooling.
abstract: OBJECTIVE
  The evoked potential recorded by a single electrode in rat's barrel cortex after whisker stimulation was shown to be composed of two main principal components shifted in time by about 3 ms. The purpose of this study was to verify the hypothesis that these components represent activity of supra- and infragranular pyramidal cell classes.
  
  
  RESULTS
  Our results show that a brief cooling pulse applied to the cortical surface abolishes the shorter latency component, which may therefore be attributed to the response of supragranular pyramidal cells.
  
  
  CONCLUSIONS
  The longer latency principal component, which disappears only with strong cooling pulses, is proposed to represent postsynaptic activity of infragranular pyramidal neurons.
authors.affiliation: Department of Neurophysiology, Nencki Institute of Experimental Biology, 3 Pasteur Street, 02-093 Warsaw, Poland.
authors.forename: E
authors.initials: E
authors.lastname: Kublik
authors.forename: P
authors.initials: P
authors.lastname: Musiał
authors.forename: A
authors.initials: A
authors.lastname: Wróbel
mesh_terms: D000818:Animals; D003080:Cold Temperature; D005071:Evoked Potentials; D008297:Male; D010812:Physical Stimulation; D017966:Pyramidal Cells / Q000502:physiology; D051381:Rats; D011930:Reaction Time / Q000502:physiology; D013003:Somatosensory Cortex / Q000502:physiology*; D013223:Statistics as Topic; D014738:Vibrissae / Q000502:physiology