Neuroanatomy of Odor Learning and Memory in Drosophila

University Of Nevada Las Vegas, Las Vegas NV

Investigators

Abstract

0237395 deBelle, John J. Neural structures and cellular components participating in associative (Pavlovian) odor learning and memory have been identified by genetic, transgenic and cell ablation studies in the fruit fly, Drosophila melanogaster. Anatomical defects in brain structures called mushroom bodies (MBs) and biochemical defects in signal transduction have each (separately) been linked to reduced learning and memory in flies. The present studies will focus on five Drosophila mutants that have reduced MB phenotypes (mbm, mbmB, mbmC, mbr and smu). The first goal is to correlate anatomical and memory defects in mutants with gene expression patterns in MBs. This will test whether genetically defined MB subdivisions are sites of specific biochemical processes underlying one or more sequential phases of memory consolidation. The second goal is to establish accurate genetic maps for the MB structure genes and to isolate new transposon-tagged mutant alleles. Brain and behavior phenotypes of these new alleles will then be characterized in P-element excision experiments. New alleles will also facilitate rapid entry to molecular analyses. For one gene (mbmB), a recently-identified transposon allele will be characterized through cloning and transgene rescue of mutant phenotypes, and by biochemical assays for levels of PKA-C1 (the suspected gene product) in mutant flies. New transposon-tagged alleles of the other MB genes will facilitate similar functional analyses. The long-term goal is to characterize MB structural gene products that function in MB development, memory consolidation, or common aspects of both. The overall significance of the proposed work is to integrate neuroanatomical and biochemical mechanisms underlying behavioral plasticity. Proposed studies will determine how functional specificity can be achieved through anatomical partitioning of relatively ubiquitous cellular mechanisms. In particular, these studies will reveal important aspects of the neural mechanisms underlying behavioral plasticity in animals and will offer unique research opportunities for students from underrepresented populations.