[Influence of limk1 Gene Polymorphism on Learning Acquisition and Memory Formation with pCREB Distribution and Aggregate Formation in Neuromuscular Junctions in Drosophila melanogaster].

We have shown previously that the polymorphic structure of the limk1 gene in drosophila leads to changes in LIMK1 content and to defects in courtship behavior, sound production, and learning/memory. The results of the present study of three wild-type strains and mutant agn(ts3) with altered limk1 structure demonstrate that long-term memory is normal in Canton-S and Oregon-R but is impaired in Berlin and drastically suppressed in agn(ts3). This temperature-sensitive mutant carries the S-element from the Tc1/mariner family insertion near the dlimk1 3'-UTR and, compared to Canton-S, has a reverse pCREB distribution in adult neuromuscular junctions (NMJ) of the second dorsal imago nerve before and after learning. Moreover, only agn(ts3) demonstrates amyloid-like aggregate formation in NMJ. This suggests that this impedes pCREb transport and thereby impairs the formation of short- and long-term memory.

[Mutations in structural genes of tryptophan metabolic enzymes of the kynurenine pathway modulate some units of the L-glutamate receptor--actin cytoskeleton signaling cascade].

Methods of immunohistochemistry and fluorescent staining was used to study the localization and amounts of protein components of the signal cascade connecting the receptor link (NMDA-subtype glutamate receptor) with actin of the cytoskeleton in the head ganglia of Drosophila strain Canton-S (wild type, control) and strains carrying mutations vermilion, cinnabar, and cardinal, which sequentially inactivate tryptophan-hydrolyzing enzymes during its metabolism into ommochrome. The obtained data are evidence for modulatory effects of genes controlling the kynurenine pathway of tryptophan metabolism on the major components of the signal cascade: the initial link (NMDA receptor, postsynaptic density protein-95, a structural protein involved in receptor localization and internalization), the intermediate link (limkinase-l, the key neuronal enzyme in actin remodeling) and the final link (f-actin, the critical factor in the morphogenesis of synaptic structures and, hence, in the processes of synaptic plasticity, learning and memory). It is suggested that kynurenine acid (an endogenous nonspecific antagonist of L-glutamate receptor) and 3-hydroxykynurenine capable of inducing a nonspecific stimulating effect are biochemical intermediates of the effects of these genes.

[Comparative analisys of localization NR1 and NR2 subunits of NMDA-receptor in the brain structures in honeybee (Apis mellifera L.) and Drosophila (Drosophila melanogaster, wild type canton-S)].

Localization NR1 and NR2 subunits of NMDA-receptor was studied in brain structures of the honeybee and Drosophila by immunohistochemistry. The Western-blotting and NR1 subunit antisense-knockdown confirmed specificity of antibodies to NR1 and NR2 subunits. The data obtained demonstrated similar distribution of NR1 and NR2 subunits of NMDA-receptor in the insect brain (cranial ganglion). The brain regions with the highest expression NR1 and NR2 were different in the honeybee and Drosophila. This can be associated with behavioral repertoire peculiarities in these insects.