%A Brette,Romain %D 2012 %J Frontiers in Computational Neuroscience %C %F %G English %K gain control,interaural time difference,Sound Localization,spike timing,spiking models %Q %R 10.3389/fncom.2011.00063 %W %L %M %P %7 %8 2012-January-10 %9 Original Research %+ Prof Romain Brette,Ecole Normale Supérieure,Département d'Etudes Cognitives,29, rue d'Ulm,Paris,75005,France,romain.brette@inserm.fr %+ Prof Romain Brette,CNRS and Université Paris Descartes,Paris,France,romain.brette@inserm.fr %# %! Spiking models for level-invariant encoding %* %< %T Spiking Models for Level-Invariant Encoding %U https://www.frontiersin.org/articles/10.3389/fncom.2011.00063 %V 5 %0 JOURNAL ARTICLE %@ 1662-5188 %X Levels of ecological sounds vary over several orders of magnitude, but the firing rate and membrane potential of a neuron are much more limited in range. In binaural neurons of the barn owl, tuning to interaural delays is independent of level differences. Yet a monaural neuron with a fixed threshold should fire earlier in response to louder sounds, which would disrupt the tuning of these neurons. How could spike timing be independent of input level? Here I derive theoretical conditions for a spiking model to be insensitive to input level. The key property is a dynamic change in spike threshold. I then show how level invariance can be physiologically implemented, with specific ionic channel properties. It appears that these ingredients are indeed present in monaural neurons of the sound localization pathway of birds and mammals.