FOCAL UNCAGING OF GLUTAMATE IN THE MUSHROOM BODIES IMPROVES OLFACTORY MEMORY IN APIS MELLIFERA

LOCATELLI F; BUNDROCK G; MENZEL R; MUELLER U

Washington DC , EEUU.

Congreso; XXXV Annual Meeting of American Society for Neurosciences (SFN),; 2005

American Society for Neurosciences

FOCAL UNCAGING OF GLUTAMATE IN THE MUSHROOM BODIES IMPROVES OLFACTORY MEMORY IN APIS MELLIFERA F.Locatelli1*; G.Bundrock1; R.Menzel1; U.Mueller1,2 1. Institut fuer Biologie-Neurobiologie, Freie Universtaet, Berlin, Germany 2. Zoologie/Physiologie, Univ. des Saarlandes, Saarbruecken, Germany In contrast to the knowledge about glutamatergic neurotransmission in the mammalian brain and its role in synaptic plasticity, the function of glutamate in the insect brain is hardly understood. This is due to the lack of pharmacological tools for insect glutamate receptors and the fact that glutamate, unlike in mammals, is the transmitter at the neuromuscular junction. Recent reports from different species provided convincing evidence for the existence of glutamate receptors in the insect brain. Moreover, down-regulation of NMDA receptor localized in the Drosophila brain leads to memory deficits after olfactory conditioning. In the present work, we investigated the function of glutamate in memory formation using associative olfactory conditioning of the proboscis extension reflex in the honeybee Apis mellifera. The honeybee provides the unique possibility to monitor and access brain functions with various techniques in the behaving animal. This allowed us to use photo-uncaging of glutamate in vivo to address the temporal and local aspects of glutamate function during olfactory conditioning. Bees were injected with caged-glutamate; antennal lobes or mushroom bodies, two brain structures involved in associative learning, were stimulated by UV-light at defined times to induce local release of glutamate. Uncaging glutamate in the mushroom bodies immediately after a weak training protocol induces formation of long-term memory that is normally acquired only after a strong training protocol. Release of glutamate before training does not facilitate memory formation, suggesting that glutamate mediates molecular processes required for long-term memory after training. Glutamate uncaging in the antennal lobes shows no effect on memory formation. Taken together, our results provide direct evidence for a temporally and locally restricted function of glutamate in the formation of long-term olfactory memory in honeybees.Support Contributed By: DAAD, DFG and Fundacion Antorchas Citation:F. Locatelli, G. Bundrock, R. Menzel, U. Mueller. FOCAL UNCAGING OF GLUTAMATE IN THE MUSHROOM BODIES IMPROVES OLFACTORY MEMORY IN APIS MELLIFERA Program No. 655.11. 2005 Abstract Viewer/Itinerary Planner. Washington, DC: Society for Neuroscience, 2005. Online. 2005 Copyright by the Society for Neuroscience all rights reserved. Permission to republish any abstract or part of any abstract in any form must be obtained in writing from the SfN office prior to publication