Somatosensory Systems, PainOptical imaging in vitro provides evidence for the minicolumnar nature of cortical responseKohn, Adam1,4; Pinheiro, Aluisio1; Tommerdahl, Mark A.2; Whitsel, Barry L.2,3Author Information 1Curriculum in Neurobiology and Departments of Statistics, 155 Medical Research, CB# 7545, University of North Carolina, Chapel Hill, NC 27599-7545, USA 2Curriculum in Neurobiology and Departments of Biomedical Engineering, 155 Medical Research, CB# 7545, University of North Carolina, Chapel Hill, NC 27599-7545, USA 3Curriculum in Neurobiology and Departments of Physiology, 155 Medical Research, CB# 7545, University of North Carolina, Chapel Hill, NC 27599-7545, USA 4Corresponding Author: Adam Kohn Received 24 July 1997; accepted 2 September 1997 NeuroReport: November 10th, 1997 - Volume 8 - Issue 16 - p 3513-3517 Buy Abstract THE response of rat neocortical slices to electrical stimulation at the layer VI/white matter border was recorded using intrinsic signal optical imaging. The optical response of the slice is column-shaped, extends from layer VI to the pial surface, and is strongly correlated with the amplitude of simultaneously recorded evoked potentials. Spectral analysis revealed radially oriented spatial variations in the intensity of the optical signal with a period of 30–60 μm/cycle. Nissl-stained sections of slices also exhibited a radially oriented periodicity in optical density with the same period. We conclude that the periodic variations in the intrinsic optical signal correspond to stimulus-activated minicolumns. © Lippincott-Raven Publishers.