scholarly journals Circuit reorganization in the Drosophila mushroom body calyx accompanies memory consolidation

2020 ◽  
Author(s):  
Lothar Baltruschat ◽  
Philipp Ranft ◽  
Luigi Prisco ◽  
J. Scott Lauritzen ◽  
André Fiala ◽  
...  
Keyword(s):  
Conditioned Stimulus ◽  
Memory Consolidation ◽  
Mushroom Body ◽  
Structural Changes ◽  
De Novo ◽  
Projection Neurons ◽  
Structural Modifications ◽  
Behavioural Experiments ◽  
The Individual ◽  
Mushroom Body Calyx

SummaryThe capacity of utilizing past experience to guide future action is a fundamental and conserved function of the nervous system. Associative memory formation initiated by the coincident detection of a conditioned stimulus (CS, e.g. odour) and an unconditioned stimulus (US, e.g. sugar reward) can lead to a short-lived memory trace (STM) within distinct circuits [1-5]. Memories can be consolidated into long-term memories (LTM) through processes that are not fully understood, but depend on de-novo protein synthesis [6, 7], require structural modifications within the involved neuronal circuits and might lead to the recruitment of additional ones [8-17]. Compared to modulation of existing connections, the reorganization of circuits affords the unique possibility of sampling for potential new partners [18-20]. Nonetheless, only few examples of rewiring associated with learning have been established thus far [14, 21-24]. Here, we report that memory consolidation is associated with the structural and functional reorganization of an identified circuit in the adult fly brain. The formation and retrieval of olfactory associative memories in Drosophila requires the mushroom body (MB) [25]. We identified the individual synapses of olfactory projection neurons (PNs) that deliver a conditioned odour to the MB and reconstructed the complexity of the microcircuit they form. Combining behavioural experiments with high-resolution microscopy and functional imaging, we demonstrated that the consolidation of appetitive olfactory memories closely correlates with an increase in the number of synaptic complexes formed by the PNs that deliver the conditioned stimulus and their postsynaptic partners. These structural changes result in additional functional synaptic connections.

Targeting expression to projection neurons that innervate specific mushroom body calyx and antennal lobe glomeruli in larval Drosophila

2010 ◽  
Vol 10 (7-8) ◽  
pp. 328-337 ◽  
Author(s):  
Liria M. Masuda-Nakagawa ◽  
Takeshi Awasaki ◽  
Kei Ito ◽  
Cahir J. O’Kane
Keyword(s):  
Mushroom Body ◽  
Antennal Lobe ◽  
Projection Neurons ◽  
Mushroom Body Calyx

scholarly journals Circuit reorganization in the Drosophila mushroom body calyx accompanies memory consolidation

Cell Reports ◽  
2021 ◽  
Vol 34 (11) ◽  
pp. 108871
Author(s):  
Lothar Baltruschat ◽  
Luigi Prisco ◽  
Philipp Ranft ◽  
J. Scott Lauritzen ◽  
André Fiala ◽  
...  
Keyword(s):  
Memory Consolidation ◽  
Mushroom Body ◽  
Mushroom Body Calyx ◽  
Circuit Reorganization

scholarly journals Octopaminergic neurons have multiple targets in Drosophila larval mushroom body calyx and regulate behavioral odor discrimination

2018 ◽  
Author(s):  
J Y Hilary Wong ◽  
Bo Angela Wan ◽  
Tom Bland ◽  
Marcella Montagnese ◽  
Alex McLachlan ◽  
...  
Keyword(s):  
Mushroom Body ◽  
Inhibitory Neuron ◽  
Odor Discrimination ◽  
Learning Ability ◽  
Projection Neurons ◽  
Input Region ◽  
Output Neurons ◽  
Mushroom Body Calyx ◽  
Intrinsic Neurons ◽  
Selection Of

AbstractDiscrimination of sensory signals is essential for an organism to form and retrieve memories of relevance in a given behavioural context. Sensory representations are modified dynamically by changes in behavioral state, facilitating context-dependent selection of behavior, through signals carried by noradrenergic input in mammals, or octopamine (OA) in insects. To understand the circuit mechanisms of this signaling, we characterized the function of two OA neurons, sVUM1 neurons, that originate in the subesophageal zone (SEZ) and target the input region of the memory center, the mushroom body (MB) calyx, in larval Drosophila. We find that sVUM1 neurons target multiple neurons, including olfactory projection neurons (PNs), the inhibitory neuron APL, and a pair of extrinsic output neurons, but relatively few mushroom body intrinsic neurons, Kenyon cells. PN terminals carried the OA receptor Oamb, a Drosophila α1-adrenergic receptor ortholog. Using an odor discrimination learning paradigm, we showed that optogenetic activation of OA neurons compromised discrimination of similar odors but not learning ability. Our results suggest that sVUM1 neurons modify odor representations via multiple extrinsic inputs at the sensory input area to the MB olfactory learning circuit.

scholarly journals Entangling Lattice-Trapped Bosons with a Free Impurity: Impact on Stationary and Dynamical Properties

Entropy ◽  
2021 ◽  
Vol 23 (3) ◽  
pp. 290
Author(s):  
Maxim Pyzh ◽  
Kevin Keiler ◽  
Simeon I. Mistakidis ◽  
Peter Schmelcher
Keyword(s):  
Structural Changes ◽  
Many Body ◽  
Wide Range ◽  
Entropy Measures ◽  
Particle Level ◽  
The Many ◽  
The One ◽  
Tunneling Dynamics ◽  
The Individual ◽  
Trapped Bosons

We address the interplay of few lattice trapped bosons interacting with an impurity atom in a box potential. For the ground state, a classification is performed based on the fidelity allowing to quantify the susceptibility of the composite system to structural changes due to the intercomponent coupling. We analyze the overall response at the many-body level and contrast it to the single-particle level. By inspecting different entropy measures we capture the degree of entanglement and intraspecies correlations for a wide range of intra- and intercomponent interactions and lattice depths. We also spatially resolve the imprint of the entanglement on the one- and two-body density distributions showcasing that it accelerates the phase separation process or acts against spatial localization for repulsive and attractive intercomponent interactions, respectively. The many-body effects on the tunneling dynamics of the individual components, resulting from their counterflow, are also discussed. The tunneling period of the impurity is very sensitive to the value of the impurity-medium coupling due to its effective dressing by the few-body medium. Our work provides implications for engineering localized structures in correlated impurity settings using species selective optical potentials.

scholarly journals Exploring Secondary Metabolite Profiles of Stachybotrys spp. by LC-MS/MS

Toxins ◽  
2019 ◽  
Vol 11 (3) ◽  
pp. 133 ◽  
Author(s):  
Annika Jagels ◽  
Viktoria Lindemann ◽  
Sebastian Ulrich ◽  
Christoph Gottschalk ◽  
Benedikt Cramer ◽  
...  
Keyword(s):  
Secondary Metabolites ◽  
Future Research ◽  
Structural Modifications ◽  
Metabolite Profiles ◽  
The Individual ◽  
First Time ◽  
Analytical Standards ◽  
Respective Species

The genus Stachybotrys produces a broad diversity of secondary metabolites, including macrocyclic trichothecenes, atranones, and phenylspirodrimanes. Although the class of the phenylspirodrimanes is the major one and consists of a multitude of metabolites bearing various structural modifications, few investigations have been carried out. Thus, the presented study deals with the quantitative determination of several secondary metabolites produced by distinct Stachybotrys species for comparison of their metabolite profiles. For that purpose, 15 of the primarily produced secondary metabolites were isolated from fungal cultures and structurally characterized in order to be used as analytical standards for the development of an LC-MS/MS multimethod. The developed method was applied to the analysis of micro-scale extracts from 5 different Stachybotrys strains, which were cultured on different media. In that process, spontaneous dialdehyde/lactone isomerization was observed for some of the isolated secondary metabolites, and novel stachybotrychromenes were quantitatively investigated for the first time. The metabolite profiles of Stachybotrys species are considerably influenced by time of growth and substrate availability, as well as the individual biosynthetic potential of the respective species. Regarding the reported adverse effects associated with Stachybotrys growth in building environments, combinatory effects of the investigated secondary metabolites should be addressed and the role of the phenylspirodrimanes re-evaluated in future research.

scholarly journals Structure-Activity Relationships of Sandalwood Odorants: Synthesis of a New Campholene Derivative

2010 ◽  
Vol 5 (9) ◽  
pp. 1934578X1000500
Author(s):  
Iris Stappen ◽  
Joris Höfinghoff ◽  
Gerhard Buchbauer ◽  
Peter Wolschann
Keyword(s):  
Structural Changes ◽  
Great Influence ◽  
Complete Loss ◽  
Side Chain ◽  
Side Chains ◽  
Quaternary Carbon ◽  
Structural Modifications ◽  
Structure Activity ◽  
Highly Sensitive ◽  
Sandalwood Odorants

Structural modifications of natural (-)-( Z)-β-santalol have shown that the sandalwood odor impression is highly sensitive, even to small structural changes. Particularly, the substitution of the quaternary carbon is of great influence on the scent. Epi-compounds with side chains in the endo-position possess sandalwood odor in only a few derivatives, whereas modifications at this side chain, as well as modification at the bicyclic ring systems mostly lead to a complete loss of sandalwood fragrance.

Structural changes induced by cation ordering in ferrotapiolite

2006 ◽  
Vol 70 (3) ◽  
pp. 319-328 ◽  
Author(s):  
M. Zema ◽  
S.C. Tarantino ◽  
A. Giorgiani
Keyword(s):  
Structural Changes ◽  
Rapid Determination ◽  
Linear Increase ◽  
X Ray Diffraction ◽  
Ionic Radii ◽  
Structural Modifications ◽  
Lattice Constants ◽  
Structure Factors ◽  
Polyhedral Volumes ◽  
Degree Of Order

AbstractStructural modifications as a function of the degree of order (Q) in FeTa2O6 ferrotapiolite have been characterized by means of single-crystal X-ray diffraction (SC-XRD). A total of 26 datasets covering the range of Q between 0.154 and 1 have been obtained by thermal treatments followed by quenching of natural tapiolite crystals. Ordering of Fe2+ at the A sites and of Ta5+ at the B sites causes a linear increase in the a/c lattice constants ratio, as a consequence of a linear decrease of the c dimension and only slight modifications of the a parameter. Calibration of a/c vs. Q represents a very useful tool for a rapid determination of the degree of order of tapiolite samples. Polyhedral volumes of the two octahedral sites vary linearly with Q as a consequence of the different ionic radii of the two species. Both the sites remain almost regular at all Q values but the B site shows an increasing off-centre displacement of the cation with increasing Q. Observed structure factors of supercell reflections, characterized by l ≠ 3n, increase linearly as a function of Q, thus representing a further tool for a quick evaluation of the degree of order.

scholarly journals Visualizing the Bohr effect in hemoglobin: neutron structure of equine cyanomethemoglobin in the R state and comparison with human deoxyhemoglobin in the T state

2016 ◽  
Vol 72 (7) ◽  
pp. 892-903 ◽  
Author(s):  
Steven Dajnowicz ◽  
Sean Seaver ◽  
B. Leif Hanson ◽  
S. Zoë Fisher ◽  
Paul Langan ◽  
...  
Keyword(s):  
Structural Changes ◽  
Accurate Determination ◽  
Bohr Effect ◽  
Salt Bridges ◽  
Histidine Residues ◽  
Regions Of Stability ◽  
The Individual ◽  
T State

Neutron crystallography provides direct visual evidence of the atomic positions of deuterium-exchanged H atoms, enabling the accurate determination of the protonation/deuteration state of hydrated biomolecules. Comparison of two neutron structures of hemoglobins, human deoxyhemoglobin (T state) and equine cyanomethemoglobin (R state), offers a direct observation of histidine residues that are likely to contribute to the Bohr effect. Previous studies have shown that the T-state N-terminal and C-terminal salt bridges appear to have a partial instead of a primary overall contribution. Four conserved histidine residues [αHis72(EF1), αHis103(G10), αHis89(FG1), αHis112(G19) and βHis97(FG4)] can become protonated/deuterated from the R to the T state, while two histidine residues [αHis20(B1) and βHis117(G19)] can lose a proton/deuteron. αHis103(G10), located in the α1:β1dimer interface, appears to be a Bohr group that undergoes structural changes: in the R state it is singly protonated/deuterated and hydrogen-bonded through a water network to βAsn108(G10) and in the T state it is doubly protonated/deuterated with the network uncoupled. The very long-term H/D exchange of the amide protons identifies regions that are accessible to exchange as well as regions that are impermeable to exchange. The liganded relaxed state (R state) has comparable levels of exchange (17.1% non-exchanged) compared with the deoxy tense state (T state; 11.8% non-exchanged). Interestingly, the regions of non-exchanged protons shift from the tetramer interfaces in the T-state interface (α1:β2and α2:β1) to the cores of the individual monomers and to the dimer interfaces (α1:β1and α2:β2) in the R state. The comparison of regions of stability in the two states allows a visualization of the conservation of fold energy necessary for ligand binding and release.

scholarly journals Pathological transitions in myelin membranes driven by environmental and multiple sclerosis conditions

2018 ◽  
Vol 115 (44) ◽  
pp. 11156-11161 ◽  
Author(s):  
Rona Shaharabani ◽  
Maor Ram-On ◽  
Yeshayahu Talmon ◽  
Roy Beck
Keyword(s):  
Multiple Sclerosis ◽  
Phase Transition ◽  
Lipid Composition ◽  
Environmental Conditions ◽  
Structural Changes ◽  
Environmental Changes ◽  
Hexagonal Phase ◽  
Structural Phase ◽  
Structural Modifications ◽  
Transition Points

Multiple sclerosis (MS) is an autoimmune disease, leading to the destruction of the myelin sheaths, the protective layers surrounding the axons. The etiology of the disease is unknown, although there are several postulated environmental factors that may contribute to it. Recently, myelin damage was correlated to structural phase transition from a healthy stack of lamellas to a diseased inverted hexagonal phase as a result of the altered lipid stoichiometry and low myelin basic protein (MBP) content. In this work, we show that environmental conditions, such as buffer salinity and temperature, induce the same pathological phase transition as in the case of the lipid composition in the absence of MBP. These phase transitions have different transition points, which depend on the lipid’s compositions, and are ion specific. In extreme environmental conditions, we find an additional dense lamellar phase and that the native lipid composition results in similar pathology as the diseased composition. These findings demonstrate that several local environmental changes can trigger pathological structural changes. We postulate that these structural modifications result in myelin membrane vulnerability to the immune system attacks and thus can help explain MS etiology.

scholarly journals RECORD: Reference-Assisted Genome Assembly for Closely Related Genomes

2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Krisztian Buza ◽  
Bartek Wilczynski ◽  
Norbert Dojer
Keyword(s):  
Reference Genome ◽  
De Novo ◽  
Real Data ◽  
Reference Sequence ◽  
Individual Genome ◽  
Single Experiment ◽  
Sequencing Technologies ◽  
Sequencing Cost ◽  
The Individual ◽  
Assembly Software

Background. Next-generation sequencing technologies are now producing multiple times the genome size in total reads from a single experiment. This is enough information to reconstruct at least some of the differences between the individual genome studied in the experiment and the reference genome of the species. However, in most typical protocols, this information is disregarded and the reference genome is used.Results. We provide a new approach that allows researchers to reconstruct genomes very closely related to the reference genome (e.g., mutants of the same species) directly from the reads used in the experiment. Our approach applies de novo assembly software to experimental reads and so-called pseudoreads and uses the resulting contigs to generate a modified reference sequence. In this way, it can very quickly, and at no additional sequencing cost, generate new, modified reference sequence that is closer to the actual sequenced genome and has a full coverage. In this paper, we describe our approach and test its implementation called RECORD. We evaluate RECORD on both simulated and real data. We made our software publicly available on sourceforge.Conclusion. Our tests show that on closely related sequences RECORD outperforms more general assisted-assembly software.

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