Localization of odor-induced neuronal activity in the antennal lobes of the blowfly Calliphora vicina: a [3H] 2-deoxyglucose labeling study.

The distribution of odor-evoked neuronal activity in the antennal lobes of the blowfly Calliphora vicina has been studied by means of [3H] 2-deoxyglucose (2-DG) uptake. Stimulation with natural attractants like meat or cheese induced uptake of 2-DG in a large number of glomeruli, stimulation with the single odorant butyric acid only in a small number of glomeruli. In control brains, the majority of glomeruli showed low 2-DG uptake. The distribution of labeled glomeruli was odor-specific and consistent in different specimen. The labeling patterns evoked by different odors overlapped partially but were clearly distinct. The highest uptake within the glomeruli was found in the axons of antennal receptor neurons. The present data provide evidence that different odors are represented as defined spatial patterns of activity across the antennal lobe glomeruli. The overlapping patterns suggest that certain glomeruli participate in the nervous processing of different odors.