HONEYBEE OLFACTORY SENSILLA BEHAVE AS INTEGRATED PROCESSING UNITS

Honeybee placode sensilla contain 18-35 olfactory receptor neurons. In insects, such neurons are thought to not interact with one another be fore reaching the central nervous system. Extracellular, multiunit rec ordings were made from the placodes and separated into spike shape cla sses, termed subplacode units. An analysis of the response spectra of subplacode units demonstrated that subplacode units with similar respo nse spectra were more likely to be found in different placodes than in the same placode. An analysis was made of the mean interspike interva ls and its variation for whole placodes and subplacode units. The coef ficient of variation for whole placodes was less than that for subplac ode units. Whole placode spike trains are therefore more uniform than subplacode spike trains, indicating that neurons might not be firing i ndependently of each other. (C) 1994 Academic Press, Inc.