Igor Siwanowicz

Learn More
The mushroom body is required for a variety of behaviors of Drosophila melanogaster. Different types of intrinsic and extrinsic mushroom body neurons might underlie its functional diversity. There have been many GAL4 driver lines identified that prominently label the mushroom body intrinsic neurons, which are known as "Kenyon cells." Under one constant(More)
Animals approach stimuli that predict a pleasant outcome. After the paired presentation of an odour and a reward, Drosophila melanogaster can develop a conditioned approach towards that odour. Despite recent advances in understanding the neural circuits for associative memory and appetitive motivation, the cellular mechanisms for reward processing in the(More)
A paired presentation of an odor and electric shock induces aversive odor memory in Drosophila melanogaster. Electric shock reinforcement is mediated by dopaminergic neurons, and it converges with the odor signal in the mushroom body (MB). Dopamine is synthesized in approximately 280 neurons that form distinct cell clusters and is involved in a variety of(More)
Animals acquire predictive values of sensory stimuli through reinforcement. In the brain of Drosophila melanogaster, activation of two types of dopamine neurons in the PAM and PPL1 clusters has been shown to induce aversive odor memory. Here, we identified the third cell type and characterized aversive memories induced by these dopamine neurons. These three(More)
Insulin-like growth factor-binding proteins (IGFBPs) control bioavailability, activity, and distribution of insulin-like growth factor (IGF)1 and -2 through high-affinity IGFBP/IGF complexes. IGF-binding sites are found on N- and C-terminal fragments of IGFBPs, the two conserved domains of IGFBPs. The relative contributions of these domains to IGFBP/IGF(More)
A fundamental duty of any efficient memory system is to prevent long-lasting storage of poorly relevant information. However, little is known about dedicated mechanisms that appropriately trigger production of long-term memory (LTM). We examined the role of Drosophila dopaminergic neurons in the control of LTM formation and found that they act as a switch(More)
Aversive olfactory memory is formed in the mushroom bodies in Drosophila melanogaster. Memory retrieval requires mushroom body output, but the manner in which a memory trace in the mushroom body drives conditioned avoidance of a learned odor remains unknown. To identify neurons that are involved in olfactory memory retrieval, we performed an anatomical and(More)
In the initiation step of bacterial protein synthesis initiation factor IF2 has to join the 30S ribosomal subunit in order to promote the binding of the fMet-tRNAMetf. In order to identify regions within IF2 which may be involved in the primary ribosome-factor interaction, we have constructed several C-terminal and N-terminal truncated forms of the factor(More)
Insulin-like growth factor binding proteins (IGFBPs) control the extracellular distribution, function, and activity of IGFs. Here, we report an X-ray structure of the binary complex of IGF-I and the N-terminal domain of IGFBP-4 (NBP-4, residues 3-82) and a model of the ternary complex of IGF-I, NBP-4, and the C-terminal domain (CBP-4, residues 151-232)(More)
The amphipod crustacean Parhyale hawaiensis is a blossoming model system for studies of developmental mechanisms and more recently regeneration. We have sequenced the genome allowing annotation of all key signaling pathways, transcription factors, and non-coding RNAs that will enhance ongoing functional studies. Parhyale is a member of the Malacostraca(More)