What is a cortical column, and how large is it? · Grey Matter

A cortical column is a vertical module running through the layers of the cortex, in which neurons share inputs and respond to related features, first described by Vernon Mountcastle in the 1950s.

What is a cortical column, and how large is it?

A cortical column is a vertical module running through the layers of the cortex, in which neurons share inputs and respond to related features, first described by Vernon Mountcastle in the 1950s. The word covers two scales: minicolumns, chains of cells about 50 micrometres across, and larger columns (macrocolumns) about 300 to 600 micrometres across, built from many minicolumns; the often-quoted figure of a millimetre is at the generous end. Each column contains pyramidal cells and inhibitory interneurons wired in a recurring microcircuit, so it is a natural unit in which to study the balance of excitation and inhibition. How sharp their boundaries are varies by area and species, and whether columns are a universal computational unit is debated.