Regrettably, an error has occurred in the reference list.

The current and incorrect reference is:

Anderson JS, Lampl I, Gillespie DC, Ferster D (2001) Membrane potential and conductance changes underlying length tuning of cells in cat primary visual cortex. J Neurosci 21: 2104–2112.

The correct reference should read:

Anderson JS, Carandini M, Ferster D (
) Orientation tuning of input conductance, excitation, and inhibition in cat primary visual cortex.
J Neurophysiol