Characterization of a metabotropic glutamate receptor in the honeybee (Apis mellifera): implications for memory formation.
G-protein-coupled metabotropic glutamate receptors (GPC mGluRs) are important constituents of glutamatergic synapses where they contribute to synaptic plasticity and development. Here we characterised a member of this family in the honeybee. We show that the honeybee genome encodes a genuine mGluR (AmGluRA) that is expressed at low to medium levels in both pupal and adult brains. Analysis of honeybee protein sequence places it within the type 3 GPCR family, which includes mGlu receptors, GABA-B receptors, calcium-sensing receptors, and pheromone receptors. Phylogenetic comparisons combined with pharmacological evaluation in HEK 293 cells transiently expressing AmGluRA show that the honeybee protein belongs to the group II mGluRs. With respect to learning and memory AmGluRA appears to be required for memory formation. Both agonists and antagonists selective against the group II mGluRs impair long-term (24 h) associative olfactory memory formation when applied 1 h before training, but have no effect when injected post-training or pre-testing. Our results strengthen the notion that glutamate is a key neurotransmitter in memory processes in the honeybee.
Kucharski
R
R
Visual Sciences and ARC Centre for the Molecular Genetics of Development, Research School of Biological Sciences, The Australian National University, Canberra, ACT 0200, Australia.
Mitri
C
C
Grau
Y
Y
Maleszka
R
R
D000595:Amino Acid Sequence; D000818:Animals; D001516:Bees / Q000502:physiology*; D001921:Brain / Q000187:drug effects / Q000502:physiology*; D018691:Excitatory Amino Acid Antagonists / Q000494:pharmacology; D006801:Humans; D015151:Immunoblotting; D017403:In Situ Hybridization; D008568:Memory / Q000187:drug effects / Q000502:physiology*; D008969:Molecular Sequence Data; D010802:Phylogeny; D018094:Receptors, Metabotropic Glutamate / Q000187:drug effects / Q000235:genetics* / Q000378:metabolism*; D017386:Sequence Homology, Amino Acid
D018691:Excitatory Amino Acid Antagonists; D018094:Receptors, Metabotropic Glutamate