Contribution of single unit analysis in insects to an understanding of olfactory function

Summary The olfactory pathway of the American cockroach is described from antennal receptor input to protocerebral output neurons. Based upon new and reviewed electrophysiological, neuroanatomical and fine structural data, connections and projections of individually identified receptor cells and central neurons are demonstrated. On the basis of investigation of input-output functions of such units modes of neural coding of naturally occurring complex odor stimuli and their constituents are proposed for the first two stages of the pathway. The role of protocerebral neurons is discussed at a functional-neuroanatomical level. A few data are added of descending neurons of moths.Abbreviations CP Copora pedunculata - MG Macroglomerulus - TOG Tractus olfactorio-globularis - LLP lateral lobe of protocerebrum