Distribution of dopamine receptors and dopamine receptor homologs in the brain of the honey bee, Apis mellifera L.

In the brain of the honey bee, Apis mellifera, the radioligands [H-3]-SCH23 390 and [H-3]-spiperone recognise D1- and D2-like receptors, respectively. In addition to being pharmacologically distinct and exhibiting significantl y different expression profiles during the lifetime of the bee, [H-3]-SCH23 390- and [H-3]-spiperone-binding sites differ markedly in their distributio n within the brain. Estimates of [H-3]-SCH23390-binding site density are hi ghest in the somatal rind, whereas [H-3]-spiperone-binding sites are most c oncentrated in the beta lobe neuropil of the mushroom bodies. Molecular clo ning techniques have been used to identify two honey bee genes encoding dop amine receptor homologs. The first is the honey bee counterpart of a Drosop hila D1-like dopamine receptor and is expressed in the mushroom bodies of b oth workers and drones. The second is related to D2-like dopamine receptors from vertebrates and is expressed in the brain of the bee, but the precise distribution of expression is not yet known. Microsc. Res. Tech. 44:179-18 9, 1999. (C) 1999 Wiley-Liss, Inc.