Age-dependent dynamics of sensitivity to agonists of central glutamate receptors in the honeybee Apis mellifera

Abstract

Earlier (1999-2002) we have shown participa� tion of central glutamate receptors (GR) in asso� ciative learning of the honeybee Apis mellifera (1, 2). The role of central ionotropic glutamate recep� tors (iGR) of the AMPAand NMDAsubtypes as well as their key subunits GR2 and HP1, respec� tively, was revealed in formation of the shortterm memory, while of metabotropic receptors (mGR)—of the longterm memory. The goal of the present work was to study, using the behavioral criterion, sensitivity of central iGR and mGR in honeybees Apis mellifera in ontogen� esis to the main glutamate agonists: NmethylD� aspartate (NMDA), kainate, 1�amino�3�hydroxy� 5�methyl�4�isooxazolpropionate (AMPA), trans� aminocyclopentadicarbonic acid (ACPD), and quisqualate. The procedure of the experiment is described in detail earlier (2). Experiments were carried out on the crain race honeybees (Apis mellifera carnica Pollm). The behavioral criterion was used—the number of honeybees preserving in memory for 1 min (shortterm memory) and 180 min (longterm memory) the elaborated conditional reaction af� ter one learning seance, a combination of an ol� factory stimulus (odor of carnation) with the un� conditional reinforcement (50% sucrose). Effects of NMDA, kainate, and AMPA on preservation of the conditional reflex were studied 1 min after the single learning seance, while those of ACPD and quisqualate—180 min later. Before the exper� iment, honeybees were deprived of food by isolat� ing them from the family for 3 h to achieve the sta�