IN THE VISUAL PATHWAY

ABSRAcrAlthough avariety oftypes ofspike interval histograms havebeen reported, little attention hasbeengiven tothespike interval distribution asaneural codeandtohowdifferent distributions aretransmitted through neural networks. Inthis paperwepresent experimental results showing spike interval histograms recorded fromretinal ganglion cells ofthecat. These results exhibit aclear correlation between spike interval distribution andstimulus condition attheretinal ganglion cell level. Theaveraged meanrates ofthecells studied werenearly thesame inlight asindarkness whereas thespike interval histograms weremuchmoreregularinlight thanindarkness. Wepresent theoretical models whichillustrate how suchadistribution coding attheretinal level could be"interpreted" orrecorded atsomehigher level ofthenervous system suchasthelateral geniculate nucleus. Interpretation isanessential requirement ofaneural codewhichhasoften been overlooked inmodeling studies. Analytical expressions arederived describing the role ofdistribution coding indetermining thetransfer characteristics ofasimple interaction modelandofalateral inhibition network. Ourworksuggests that distribution coding mightbeinterpreted bysimply interconnected neural networks suchasrelay cell networks, ingeneral, andtheprimary thalamic sensory nuclei in