scholarly journals Olfactory sensory preconditioning in Drosophila: role of memory forgetting in gating S1/S2 associations

2021 ◽  
Author(s):  
Anna Phan ◽  
Juan Carlos Martinez Cervantes ◽  
Isaac Cervantes Sandoval
Keyword(s):  
Predictive Power ◽  
Memory Storage ◽  
Sensory Preconditioning ◽  
Conditional Response ◽  
Real Nature ◽  
Small G Protein ◽  
Complex Process ◽  
Electric Shocks ◽  
Behavioral Evidence

Learning and memory storage is a complex process that has proven challenging to tackle. It is likely that, in real nature, the instructive value of reinforcing experiences is acquired rather than innate. The association between seemingly neutral stimuli increases the gamut of possibilities to create meaningful associations and increases the predictive power of moment-by-moment experiences. Here we report physiological and behavioral evidence of olfactory unimodal sensory preconditioning in fruit flies. We show that the presentation of a pair of odors (S1 and S2) before one of them (S1) is associated with electric shocks elicits a conditional response not only to the trained odor (S1) but to the odor previously paired with it (S2). This occurs even if the S2 odor was never presented in contiguity with the aversive stimulus. In addition, we show that inhibition of the small G protein and known forgetting regulator Rac1 facilitates the association between S1/S2 odors. These results indicate that flies can infer value to non-paired odor based on the previous associative structure between odors, and inhibition of Rac1 lengthens the time of olfactory sensory buffer, allowing linking of neutral odors presented in sequence.

scholarly journals Panoramic visual representation in the dorsal visual pathway and its role in reorientation

2019 ◽  
Author(s):  
Tianyi Li ◽  
Angelo Arleo ◽  
Denis Sheynikhovich
Keyword(s):  
Visual Information ◽  
Time Integration ◽  
Visual Space ◽  
Memory Storage ◽  
Imaging Data ◽  
Natural Behavior ◽  
Spatial Reorientation ◽  
Behavioral Evidence ◽  
Spiking Neural Network Model

AbstractWhile primates are primarily visual animals, how visual information is processed on its way to memory structures and contributes to the generation of visuospatial behaviors is poorly understood. Recent imaging data demonstrate the existence of scene-sensitive areas in the dorsal visual path that are likely to combine visual information from successive egocentric views, while behavioral evidence indicates the memory of surrounding visual space in extraretinal coordinates. The present work focuses on the computational nature of a panoramic representation that is proposed to link visual and mnemonic functions during natural behavior. In a spiking neural network model of the dorsal visual path it is shown how time-integration of spatial views can give rise to such a representation and how it can subsequently be used to perform memory-based spatial reorientation and visual search. More generally, the model predicts a common role of view-based allocentric memory storage in spatial and non-spatial mnemonic behaviors.

Social Cohesion, Breaks, and Transformations in Italy, 535–600

2018 ◽  
Author(s):  
Walter Pohl
Keyword(s):  
The Political ◽  
Late Antique ◽  
Religious Context ◽  
Ancient Society ◽  
Complex Process ◽  
Term Change ◽  
Two Generations ◽  
Classical Culture

When the Gothic War began in Italy in 535, the country still conserved many features of classical culture and late antique administration. Much of that was lost in the political upheavals of the following decades. Building on Chris Wickham’s work, this contribution sketches an integrated perspective of these changes, attempting to relate the contingency of events to the logic of long-term change, discussing political options in relation to military and economic means, and asking in what ways the erosion of consensus may be understood in a cultural and religious context. What was the role of military entrepreneurs of more or less barbarian or Roman extraction in the distribution or destruction of resources? How did Christianity contribute to the transformation of ancient society? The old model of barbarian invasions can contribute little to understanding this complex process. It is remarkable that for two generations, all political strategies in Italy ultimately failed.

scholarly journals Consciousness, decision making, and volition: freedom beyond chance and necessity

2021 ◽  
Author(s):  
Hans Liljenström
Keyword(s):  
Decision Making ◽  
Free Will ◽  
Brain Activity ◽  
Brain Structures ◽  
Complex Process ◽  
Neural Information ◽  
Neural Information Processing ◽  
Stochastic Population Model ◽  
The Brain

AbstractWhat is the role of consciousness in volition and decision-making? Are our actions fully determined by brain activity preceding our decisions to act, or can consciousness instead affect the brain activity leading to action? This has been much debated in philosophy, but also in science since the famous experiments by Libet in the 1980s, where the current most common interpretation is that conscious free will is an illusion. It seems that the brain knows, up to several seconds in advance what “you” decide to do. These studies have, however, been criticized, and alternative interpretations of the experiments can be given, some of which are discussed in this paper. In an attempt to elucidate the processes involved in decision-making (DM), as an essential part of volition, we have developed a computational model of relevant brain structures and their neurodynamics. While DM is a complex process, we have particularly focused on the amygdala and orbitofrontal cortex (OFC) for its emotional, and the lateral prefrontal cortex (LPFC) for its cognitive aspects. In this paper, we present a stochastic population model representing the neural information processing of DM. Simulation results seem to confirm the notion that if decisions have to be made fast, emotional processes and aspects dominate, while rational processes are more time consuming and may result in a delayed decision. Finally, some limitations of current science and computational modeling will be discussed, hinting at a future development of science, where consciousness and free will may add to chance and necessity as explanation for what happens in the world.

scholarly journals GLP-1 Receptor Stimulation of the Lateral Parabrachial Nucleus Reduces Food Intake: Neuroanatomical, Electrophysiological, and Behavioral Evidence

Endocrinology ◽  
2014 ◽  
Vol 155 (11) ◽  
pp. 4356-4367 ◽  
Author(s):  
Jennifer E. Richard ◽  
Imre Farkas ◽  
Fredrik Anesten ◽  
Rozita H. Anderberg ◽  
Suzanne L. Dickson ◽  
...  
Keyword(s):  
Feeding Behavior ◽  
Fluorescent Protein ◽  
Yellow Fluorescent Protein ◽  
Parabrachial Nucleus ◽  
Lateral Parabrachial Nucleus ◽  
Electrophysiological Studies ◽  
Glucagon Like Peptide 1 ◽  
Behavioral Evidence ◽  
Stimulation Of

Abstract The parabrachial nucleus (PBN) is a key nucleus for the regulation of feeding behavior. Inhibitory inputs from the hypothalamus to the PBN play a crucial role in the normal maintenance of feeding behavior, because their loss leads to starvation. Viscerosensory stimuli result in neuronal activation of the PBN. However, the origin and neurochemical identity of the excitatory neuronal input to the PBN remain largely unexplored. Here, we hypothesize that hindbrain glucagon-like peptide 1 (GLP-1) neurons provide excitatory inputs to the PBN, activation of which may lead to a reduction in feeding behavior. Our data, obtained from mice expressing the yellow fluorescent protein in GLP-1-producing neurons, revealed that hindbrain GLP-1-producing neurons project to the lateral PBN (lPBN). Stimulation of lPBN GLP-1 receptors (GLP-1Rs) reduced the intake of chow and palatable food and decreased body weight in rats. It also activated lPBN neurons, reflected by an increase in the number of c-Fos-positive cells in this region. Further support for an excitatory role of GLP-1 in the PBN is provided by electrophysiological studies showing a remarkable increase in firing of lPBN neurons after Exendin-4 application. We show that within the PBN, GLP-1R activation increased gene expression of 2 energy balance regulating peptides, calcitonin gene-related peptide (CGRP) and IL-6. Moreover, nearly 70% of the lPBN GLP-1 fibers innervated lPBN CGRP neurons. Direct intra-lPBN CGRP application resulted in anorexia. Collectively, our molecular, anatomical, electrophysiological, pharmacological, and behavioral data provide evidence for a functional role of the GLP-1R for feeding control in the PBN.

Assessing the Role of Selective Fossilization Hypothesis in Determining Fossilizable Phonetic Errors in Tunisian EFL Learners’ Oral Output

2020 ◽  
Vol 2 ◽  
pp. 1-15
Author(s):  
Aicha Rahal ◽  
Chokri Smaoui
Keyword(s):  
Second Language ◽  
Longitudinal Study ◽  
Predictive Power ◽  
Rating Scale ◽  
First Language ◽  
Linguistic Features ◽  
Efl Learners ◽  
Phonetic Errors ◽  
Linguistic Phenomenon

Fossilization is said to be a distinctive characteristic of second language (L2) learning (Selinker, 1972, 1996; Han, 2004). It is the most pervasive among adult L2 learners (Han and Odlin, 2006). This linguistic phenomenon has been characterized by cessation of learning, even though the learner is exposed to frequent input. Based on the findings of the MA dissertation of the first researcher which is about ‘phonetic fossilization’ and where she conducted a longitudinal study, Han’s Selective Fossilization Hypothesis (SFL) is used to analyze the obtained fossilized phonetic errors in relation to L1 markedness and L2 robustness with a particular focus on fossilized vowel sounds. This is an analytical model for identifying both acquisitional and fossilizable linguistic features based on learners’ first language (L1) markedness and second language (L2) robustness. The article first gives an overview of the theory of Interlanguage and the phenomenon of fossilization. Then, it introduces SFL. This is an attempt to study fossilization scientifically. In other words, it tests the predictive power of a developed L1 Markedness and L2 Robustness rating scale based on Han’s (2009) model. The present study has pedagogic implications; it is an opportunity to raise teachers’ awareness on this common linguistic phenomenon.

scholarly journals Role of the periodic table in discovery of new elements

2011 ◽  
Vol 1 (1) ◽  
pp. 1-5 ◽  
Author(s):  
D.C. Hoffman
Keyword(s):  
Periodic Table ◽  
Predictive Power ◽  
Chemical Elements ◽  
Chemical Properties ◽  
Negative Effects ◽  
Current Form ◽  
Future Role ◽  
History Of ◽  
Chemical Techniques

AbstractThis year (2009) marks the 140th Anniversary of Mendeleev's original 1869 periodic table of the elements based on atomic weights. It also marks the 175th anniversary of his birth in Tolbosk, Siberia. The history of the development of periodic tables of the chemical elements is briefly reviewed beginning with the presentation by Dmitri Mendeleev and his associate Nikolai Menshutkin of their original 1869 table based on atomic weights. The value, as well as the sometimes negative effects, of periodic tables in guiding the discovery of new elements based on their predicted chemical properties is assessed. It is noteworthy that the element with Z=101 (mendelevium) was identified in 1955 using chemical techniques. The discoverers proposed the name mendelevium to honor the predictive power of the Mendeleev Periodic Table. Mendelevium still remains the heaviest element to have been identified first by chemical rather than nuclear or physical techniques. The question concerning whether there will be a future role for the current form of the periodic table in predicting chemical properties and aid in the identification of elements beyond those currently known is considered.

scholarly journals Revisiting the Organic Template Model through the Microstructural Study of Shell Development in Pinctada margaritifera, the Polynesian Pearl Oyster

Minerals ◽  
2018 ◽  
Vol 8 (9) ◽  
pp. 370 ◽  
Author(s):  
Jean-Pierre Cuif ◽  
Yannicke Dauphin ◽  
Gilles Luquet ◽  
Kadda Medjoubi ◽  
Andrea Somogyi ◽  
...  
Keyword(s):  
Pearl Oyster ◽  
Nacreous Layer ◽  
Prismatic Layer ◽  
Pinctada Margaritifera ◽  
Microstructural Study ◽  
Leading Role ◽  
Complex Process ◽  
Gathering Data

A top-down approach to the mineralized structures and developmental steps that can be separated in the shells of Pinctada margaritifera was carried out. Detailed characterizations show that each of the two major layers usually taken into account (the outer prismatic layer and the inner nacreous layer) is actually the result of a complex process during which the microstructural patterns were progressively established. From its early growing stages in the deeper part of the periostracal grove up to the formation of the most inner nacreous layers, this species provides a demonstrative case study illustrating the leading role of specifically secreted organic structures as determinants of the crystallographic properties of the shell-building units. Gathering data established at various observational scales ranging from morphology to the nanometer level, this study allows for a reexamination of the recent and current biomineralization models.

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