Role of chaotic dynamics in neural plasticity

Author(s):  
Walter J. Freeman
2018 ◽  
Vol 2 ◽  
pp. 239821281879483 ◽  
Author(s):  
John P. Aggleton ◽  
Richard G. M. Morris

This review brings together past and present achievements in memory research, ranging from molecular to psychological discoveries. Despite some false starts, major advances include our growing understanding of learning-related neural plasticity and the characterisation of different classes of memory. One striking example is the ability to reactivate targeted neuronal ensembles so that an animal will seemingly re-experience a particular memory, with the further potential to modify such memories. Meanwhile, human functional imaging studies can distinguish individual episodic memories based on voxel activation patterns. While the hippocampus continues to provide a rich source of information, future progress requires broadening our research to involve other sites. Related challenges include the need to understand better the role of glial–neuron interactions and to look beyond the synapse as the sole site of experience-dependent plasticity. Unmet goals include translating our neuroscientific knowledge in order to optimise learning and memory, especially among disadvantaged populations.


1999 ◽  
Vol 218 (5-6) ◽  
Author(s):  
Michael Neugart

SummaryEvidence on the role of chaotic and nonlinear dynamics on labor markets is mixed. It is unclear whether nonlinear relationships are responsible for the dynamic patterns observed in Europe during the past decades. In this paper, we test German labor market data for the null hypothesis of an i.i.d. process with the BDS test. As several processes including chaotic, nonlinear deterministic, and stochastic linear and nonlinear systems are nested within the alternative hypothesis, time series are whitened with linear and nonlinear filters. Lyapunov exponents and correlation dimensions are applied to the residuals of the filtered time series to test for chaotic dynamics. There seems to be a nonlinear deterministic core to German labor market dynamics. Chaos does not occur.


2019 ◽  
Vol 18 (1) ◽  
pp. 2-13
Author(s):  
Michal Rychlik ◽  
Katarzyna Mlyniec

: With more people reaching an advanced age in modern society, there is a growing need for strategies to slow down age-related neuropathology and loss of cognitive functions, which are a hallmark of Alzheimer's disease. Neuroprotective drugs and candidate drug compounds target one or more processes involved in the neurodegenerative cascade, such as excitotoxicity, oxidative stress, misfolded protein aggregation and/or ion dyshomeostasis. A growing body of research shows that a G-protein coupled zinc (Zn2+) receptor (GPR39) can modulate the abovementioned processes. : Zn2+itself has a diverse activity profile at the synapse, and by binding to numerous receptors, it plays an important role in neurotransmission. However, Zn2+ is also necessary for the formation of toxic oligomeric forms of amyloid beta, which underlie the pathology of Alzheimer’s disease. Furthermore, the binding of Zn2+ by amyloid beta causes a disruption of zincergic signaling, and recent studies point to GPR39 and its intracellular targets being affected by amyloid pathology. : In this review, we present neurobiological findings related to Zn2+ and GPR39, focusing on its signaling pathways, neural plasticity, interactions with other neurotransmission systems, as well as on the effects of pathophysiological changes observed in Alzheimer's disease on GPR39 function. : Direct targeting of the GPR39 might be a promising strategy for the pharmacotherapy of zincergic dyshomeostasis observed in Alzheimer’s disease. The information presented in this article will hopefully fuel further research into the role of GPR39 in neurodegeneration and help in identifying novel therapeutic targets for dementia.


2019 ◽  
Vol 2019 ◽  
pp. 1-3 ◽  
Author(s):  
Andrea Guerra ◽  
Matteo Feurra ◽  
Giovanni Pellegrino ◽  
John-Stuart Brittain

2017 ◽  
Vol 27 (10) ◽  
pp. 1750156 ◽  
Author(s):  
K. G. D. Sulalitha Priyankara ◽  
Sanjeeva Balasuriya ◽  
Erik Bollt

We analyze chaos in the well-known nonautonomous Double-Gyre system. A key focus is on folding, which is possibly the less-studied aspect of the “stretching+folding=chaos” mantra of chaotic dynamics. Despite the Double-Gyre not having the classical homoclinic structure for the usage of the Smale–Birkhoff theorem to establish chaos, we use the concept of folding to prove the existence of an embedded horseshoe map. We also show how curvature of manifolds can be used to identify fold points in the Double-Gyre. This method is applicable to general nonautonomous flows in two dimensions, defined for either finite or infinite times.


2008 ◽  
Vol 20 (3) ◽  
pp. 745-774 ◽  
Author(s):  
Theodore P. Beauchaine ◽  
Emily Neuhaus ◽  
Sharon L. Brenner ◽  
Lisa Gatzke-Kopp

AbstractMost contemporary accounts of psychopathology acknowledge the importance of both biological and environmental influences on behavior. In developmental psychopathology, multiple etiological mechanisms for psychiatric disturbance are well recognized, including those operating at genetic, neurobiological, and environmental levels of analysis. However, neuroscientific principles are rarely considered in current approaches to prevention or intervention. In this article, we explain why a deeper understanding of the genetic and neural substrates of behavior is essential for the next generation of preventive interventions, and we outline 10 specific reasons why considering biological processes can improve treatment efficacy. Among these, we discuss (a) the role of biomarkers and endophenotypes in identifying those most in need of prevention; (b) implications for treatment of genetic and neural mechanisms of homotypic comorbidity, heterotypic comorbidity, and heterotypic continuity; (c) ways in which biological vulnerabilities moderate the effects of environmental experience; (d) situations in which Biology × Environment interactions account for more variance in key outcomes than main effects; and (e) sensitivity of neural systems, via epigenesis, programming, and neural plasticity, to environmental moderation across the life span. For each of the 10 reasons outlined we present an example from current literature and discuss critical implications for prevention.


2017 ◽  
Vol 2017 ◽  
pp. 1-11 ◽  
Author(s):  
Zhilu Zou ◽  
Yin Chen ◽  
Qinqin Shen ◽  
Xiaoyan Guo ◽  
Yuxuan Zhang ◽  
...  

Yueju pill is a traditional Chinese medicine formulated to treat syndromes of mood disorders. Here, we investigated the therapeutic effect of repeated low dose of Yueju in the animal model mimicking clinical long-term depression condition and the role of neural plasticity associated with PKA- (protein kinase A-) CREB (cAMP response element binding protein) and NMDA (N-methyl-D-aspartate) signaling. We showed that a single low dose of Yueju demonstrated antidepressant effects in tests of tail suspension, forced swim, and novelty-suppressed feeding. A chronic learned helplessness (LH) protocol resulted in a long-term depressive-like condition. Repeated administration of Yueju following chronic LH remarkably alleviated all of depressive-like symptoms measured, whereas conventional antidepressant fluoxetine only showed a minor improvement. In the hippocampus, Yueju and fluoxetine both normalized brain-derived neurotrophic factor (BDNF) and PKA level. Only Yueju, not fluoxetine, rescued the deficits in CREB signaling. The chronic LH upregulated the expression of NMDA receptor subunits NR1, NR2A, and NR2B, which were all attenuated by Yueju. Furthermore, intracerebraventricular administration of NMDA blunted the antidepressant effect of Yueju. These findings supported the antidepressant efficacy of repeated routine low dose of Yueju in a long-term depression model and the critical role of CREB and NMDA signaling.


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