scholarly journals BACE inhibition-dependent repair of Alzheimer’s pathophysiology

2017 ◽  
Vol 114 (32) ◽  
pp. 8631-8636 ◽  
Author(s):  
Aylin D. Keskin ◽  
Maja Kekuš ◽  
Helmuth Adelsberger ◽  
Ulf Neumann ◽  
Derya R. Shimshek ◽  
...  
Keyword(s):  
Neural Circuit ◽  
Cognitive Impairments ◽  
Amyloid Β ◽  
Pathogenic Role ◽  
Memory Impairments ◽  
Wide Range ◽  
Key Enzyme ◽  
Potential Benefits ◽  
Circuit Function

Amyloid-β (Aβ) is thought to play an essential pathogenic role in Alzheimer´s disease (AD). A key enzyme involved in the generation of Aβ is the β-secretase BACE, for which powerful inhibitors have been developed and are currently in use in human clinical trials. However, although BACE inhibition can reduce cerebral Aβ levels, whether it also can ameliorate neural circuit and memory impairments remains unclear. Using histochemistry, in vivo Ca2+ imaging, and behavioral analyses in a mouse model of AD, we demonstrate that along with reducing prefibrillary Aβ surrounding plaques, the inhibition of BACE activity can rescue neuronal hyperactivity, impaired long-range circuit function, and memory defects. The functional neuronal impairments reappeared after infusion of soluble Aβ, mechanistically linking Aβ pathology to neuronal and cognitive dysfunction. These data highlight the potential benefits of BACE inhibition for the effective treatment of a wide range of AD-like pathophysiological and cognitive impairments.

scholarly journals From Unpleasant to Unbearable—Why and How to Implement an Upper Limit to Pain And Other Forms of Suffering in Research with Animals

ILAR Journal ◽  
2020 ◽  
Author(s):  
I Anna S Olsson ◽  
Christine J Nicol ◽  
Steven M Niemi ◽  
Peter Sandøe
Keyword(s):  
Animal Experiments ◽  
The European Union ◽  
Animal Suffering ◽  
Social Functions ◽  
In Vivo Assays ◽  
Negative State ◽  
Wide Range ◽  
Potential Benefits ◽  
Degree Of Control

Abstract The focus of this paper is the requirement that the use of live animals in experiments and in vivo assays should never be allowed if those uses involve severe suffering. This requirement was first implemented in Danish legislation, was later adopted by the European Union, and has had limited uptake in North America. Animal suffering can arise from exposure to a wide range of different external and internal events that threaten biological or social functions, while the severity of suffering may be influenced by the animals’ perceptions of their own situation and the degree of control they are able to exert. Severe suffering is more than an incremental increase in negative state(s) but involves a qualitative shift whereby the normal mechanisms to contain or keep negative states at arm’s length no longer function. The result of severe suffering will be a loss of the ability of cope. The idea of putting a cap on severe suffering may be justified from multiple ethical perspectives. In most, if not all, cases it is possible to avoid imposing severe suffering on animals during experiments without giving up the potential benefits of finding new ways to cure, prevent, or alleviate serious human diseases and generate other important knowledge. From this it follows that there is a strong ethical case to favor a regulatory ban on animal experiments involving severe suffering.

scholarly journals Aβ42 fibril formation from predominantly oligomeric samples suggests a link between oligomer heterogeneity and fibril polymorphism

2019 ◽  
Vol 6 (7) ◽  
pp. 190179 ◽  
Author(s):  
Christine Xue ◽  
Joyce Tran ◽  
Hongsu Wang ◽  
Giovanna Park ◽  
Frederick Hsu ◽  
...  
Keyword(s):  
Growth Rate ◽  
Green Tea ◽  
Epigallocatechin Gallate ◽  
Amyloid Β ◽  
Lag Time ◽  
Aβ Oligomers ◽  
Wide Range ◽  
Aβ Aggregation

Amyloid-β (Aβ) oligomers play a central role in the pathogenesis of Alzheimer's disease. Oligomers of different sizes, morphology and structures have been reported in both in vivo and in vitro studies, but there is a general lack of understanding about where to place these oligomers in the overall process of Aβ aggregation and fibrillization. Here, we show that Aβ42 spontaneously forms oligomers with a wide range of sizes in the same sample. These Aβ42 samples contain predominantly oligomers, and they quickly form fibrils upon incubation at 37°C. When fractionated using ultrafiltration filters, the samples enriched with smaller oligomers form fibrils at a faster rate than the samples enriched with larger oligomers, with both a shorter lag time and faster fibril growth rate. This observation is independent of Aβ42 batches and hexafluoroisopropanol treatment. Furthermore, the fibrils formed by the samples enriched with larger oligomers are more readily solubilized by epigallocatechin gallate, a main catechin component of green tea. These results suggest that the fibrils formed by larger oligomers may adopt a different structure from fibrils formed by smaller oligomers, pointing to a link between oligomer heterogeneity and fibril polymorphism.

scholarly journals Beyond excitation/inhibition imbalance in multidimensional models of neural circuit changes in brain disorders

2016 ◽  
Author(s):  
Cian O’Donnell ◽  
J. Tiago Gonçalves ◽  
Carlos Portera-Cailliau ◽  
Terrence J. Sejnowski
Keyword(s):  
Neural Circuit ◽  
Fragile X ◽  
Brain Disorders ◽  
Imaging Data ◽  
Neural Firing ◽  
Knock Out ◽  
Brain Circuitry ◽  
Circuit Function ◽  
Cellular Components

AbstractA leading theory holds that neurodevelopmental brain disorders arise from imbalances in excitatory and inhibitory (E/I) brain circuitry. However, it is unclear whether this onedimensional model is rich enough to capture the multiple neural circuit alterations underlying brain disorders. Here we combined computational simulations with analysis of in vivo 2-photon Ca2+ imaging data from somatosensory cortex of Fmr1 knock-out (KO) mice, a model of Fragile-X Syndrome, to test the E/I imbalance theory. We found that: 1) The E/I imbalance model cannot account for joint alterations in the observed neural firing rates and correlations; 2) Neural circuit function is vastly more sensitive to changes in some cellular components over others; 3) The direction of circuit alterations in Fmr1 KO mice changes across development. These findings suggest that the basic E/I imbalance model should be updated to higher-dimensional models that can better capture the multidimensional computational functions of neural circuits.

scholarly journals Beyond excitation/inhibition imbalance in multidimensional models of neural circuit changes in brain disorders

eLife ◽  
2017 ◽  
Vol 6 ◽  
Author(s):  
Cian O'Donnell ◽  
J Tiago Gonçalves ◽  
Carlos Portera-Cailliau ◽  
Terrence J Sejnowski
Keyword(s):  
Neural Circuit ◽  
Fragile X ◽  
Brain Disorders ◽  
Imaging Data ◽  
Neural Firing ◽  
Knock Out ◽  
Brain Circuitry ◽  
Circuit Function ◽  
Cellular Components

A leading theory holds that neurodevelopmental brain disorders arise from imbalances in excitatory and inhibitory (E/I) brain circuitry. However, it is unclear whether this one-dimensional model is rich enough to capture the multiple neural circuit alterations underlying brain disorders. Here, we combined computational simulations with analysis of in vivo two-photon Ca2+ imaging data from somatosensory cortex of Fmr1 knock-out (KO) mice, a model of Fragile-X Syndrome, to test the E/I imbalance theory. We found that: (1) The E/I imbalance model cannot account for joint alterations in the observed neural firing rates and correlations; (2) Neural circuit function is vastly more sensitive to changes in some cellular components over others; (3) The direction of circuit alterations in Fmr1 KO mice changes across development. These findings suggest that the basic E/I imbalance model should be updated to higher dimensional models that can better capture the multidimensional computational functions of neural circuits.

Microfluidic neural axon diode

TECHNOLOGY ◽  
2016 ◽  
Vol 04 (04) ◽  
pp. 240-248 ◽  
Author(s):  
Sangcheol Na ◽  
Myeongwoo Kang ◽  
Seokyoung Bang ◽  
Daehun Park ◽  
Jinhyun Kim ◽  
...  
Keyword(s):  
Neural Circuit ◽  
Axon Growth ◽  
In Vivo Models ◽  
Starting Point ◽  
Wide Range ◽  
Reproducible Method ◽  
Physical And Chemical ◽  
Biology Research

Neural circuits, groups of neurons connected in directional manner, play a central role in information processing. Advances in neuronal biology research is limited by a lack of appropriate in vitro methods to construct and probe neuronal networks. Here, we describe a microfluidic culture platform that directs the growth of axons using “neural diode” structures to control neural connectivity. This platform is compatible with live cell imaging and can be used to (i) form pre-synaptic and postsynaptic neurons by directional axon growth and (ii) localize physical and chemical treatment to pre- or postsynaptic neuron groups (i.e. virus infection and etc.). The “neural diode” design consist of a microchannel that split into two branches: one is directed straight toward while the other returns back toward the starting point in a closed loop to send the axons back to the origin. We optimized the “neural diode” pattern dimension and design to achieve close to 70% directionality with a single unit of the “diode”. When repeated 3 times, near perfect (98–100% at wide range of cell concentrations) directionality can be achieved. The living neural circuit was characterized using Ca imaging and confirmed their function. The platform also serves as a straightforward, reproducible method to recapitulate a variety of neural circuit in vitro that were previously observable only in brain slice or in vivo models. The microfluidic neural diode may lead to better models for understanding the neural circuit and neurodegenerative diseases.

Oxytocin, Neural Plasticity, and Social Behavior

2021 ◽  
Vol 44 (1) ◽  
Author(s):  
Robert C. Froemke ◽  
Larry J. Young
Keyword(s):  
Social Behavior ◽  
Neural Plasticity ◽  
Neural Circuit ◽  
Social Behaviors ◽  
Neuron Activity ◽  
Annual Review ◽  
Publication Date ◽  
Social Stimuli ◽  
Circuit Function

Oxytocin regulates parturition, lactation, parental nurturing, and many other social behaviors in both sexes. The circuit mechanisms by which oxytocin modulates social behavior are receiving increasing attention. Here, we review recent studies on oxytocin modulation of neural circuit function and social behavior, largely enabled by new methods of monitoring and manipulating oxytocin or oxytocin receptor neurons in vivo. These studies indicate that oxytocin can enhance the salience of social stimuli and increase signal-to-noise ratios by modulating spiking and synaptic plasticity in the context of circuits and networks. We highlight oxytocin effects on social behavior in nontraditional organisms such as prairie voles and discuss opportunities to enhance the utility of these organisms for studying circuit-level modulation of social behaviors. We then discuss recent insights into oxytocin neuron activity during social interactions. We conclude by discussing some of the major questions and opportunities in the field ahead. Expected final online publication date for the Annual Review of Neuroscience, Volume 44 is July 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

Investigation of anti-Alzheimer’s activity of aqueous extract of areca nuts (Areca catechu L.): In vitro and in vivo studies

2021 ◽  
Vol 20 (4) ◽  
pp. 406-415
Author(s):  
Mahboubeh Bozorgi ◽  
◽  
Zahra Najafi ◽  
Sahar Omidpanah ◽  
Arash Sadri ◽  
...  
Keyword(s):  
Aqueous Extract ◽  
Neurodegenerative Disorder ◽  
Amyloid Β ◽  
In Vivo Studies ◽  
Memory Impairments ◽  
Age Related ◽  
Areca Catechu ◽  
Aβ Aggregation

Alzheimer’s disease (AD) is an age-related neurodegenerative disorder. Sever cognitive and memory impairments, huge increase in the prevalence of the disease, and lacking definite cure have absorbed worldwide efforts to develop therapeutic approaches. Since many drugs have failed in the clinical trials due to multifactorial nature of AD, symptomatic treatments are still in the center attention and now, nootropic medicinal plants have been found as versatile ameliorators to reverse memory disorders. In this work, anti-Alzheimer’s activity of aqueous extract of areca nuts (Areca catechu L.) was investigated via in vitro and in vivo studies. It depicted good amyloid β (Aβ) aggregation inhibitory activity, 82% at 100 µg/mL. In addition, it inhibited beta-secretase 1 (BACE1) with IC50 value of 19.03 µg/mL. Evaluation of neuroprotectivity of the aqueous extract of the plant against H2O2-induced cell death in PC12 neurons revealed 84.5% protection at 1 µg/mL. It should be noted that according to our results obtained from Morris Water Maze (MWM) test, the extract reversed scopolamine-induced memory deficit in rats at concentrations of 1.5 and 3 mg/kg.

scholarly journals Store-independent modulation of Ca2+ entry through Orai by Septin 7

2016 ◽  
Vol 7 (1) ◽  
Author(s):  
Bipan Kumar Deb ◽  
Trayambak Pathak ◽  
Gaiti Hasan
Keyword(s):  
Neural Circuit ◽  
Cell Types ◽  
Negative Regulator ◽  
Flight Duration ◽  
Multiple Cell ◽  
Circuit Function ◽  
Trisphosphate Receptor ◽  
Molecular Brake ◽  
Orai Channels

Abstract Orai channels are required for store-operated Ca2+ entry (SOCE) in multiple cell types. Septins are a class of GTP-binding proteins that function as diffusion barriers in cells. Here we show that Septin 7 acts as a ‘molecular brake’ on activation of Orai channels in Drosophila neurons. Lowering Septin 7 levels results in dOrai-mediated Ca2+ entry and higher cytosolic Ca2+ in resting neurons. This Ca2+ entry is independent of depletion of endoplasmic reticulum Ca2+ stores and Ca2+ release through the inositol-1,4,5-trisphosphate receptor. Importantly, store-independent Ca2+ entry through Orai compensates for reduced SOCE in the Drosophila flight circuit. Moreover, overexpression of Septin 7 reduces both SOCE and flight duration, supporting its role as a negative regulator of Orai channel function in vivo. Septin 7 levels in neurons can, therefore, alter neural circuit function by modulating Orai function and Ca2+ homeostasis.

scholarly journals An Overview of New Insights into the Benefits of the Seagrass Posidonia oceanica for Human Health

Marine Drugs ◽  
2021 ◽  
Vol 19 (9) ◽  
pp. 476 ◽  
Author(s):  
Marzia Vasarri ◽  
Anna Maria De Biasi ◽  
Emanuela Barletta ◽  
Carlo Pretti ◽  
Donatella Degl’Innocenti
Keyword(s):  
Human Health ◽  
Posidonia Oceanica ◽  
Experimental Investigations ◽  
Wide Range ◽  
Potential Benefits ◽  
Ecological Importance ◽  
New Research ◽  
Promising Source

Posidonia oceanica (L.) Delile is a Mediterranean-endemic angiosperm often described for its great ecological importance. Despite evidence of a millennia-old relationship between P. oceanica and humans, as well as traditional medicine applications, the potential benefits of P. oceanica for human health have been documented only recently. This review aims to compile newly acquired knowledge on P. oceanica bioactive properties that allow the scientific community to look at this plant as a promising source of natural therapeutical products for human health. Experimental investigations conducted in both in vitro cellular-based and in vivo animal models pave the way for new research projects aiming at the development of alternative and complementary therapeutic strategies based on P. oceanica against a wide range of pathological conditions.

scholarly journals A molecular logic of sensory coding revealed by optical tagging of physiologically-defined neuronal types

2019 ◽  
Author(s):  
Donghoon Lee ◽  
Maiko Kume ◽  
Timothy E Holy
Keyword(s):  
Neural Circuit ◽  
Strong Predictor ◽  
Ectopic Expression ◽  
Cell Types ◽  
Specific Cell ◽  
Molecular Logic ◽  
Neuronal Types ◽  
A Cell ◽  
Circuit Function

Neural circuit analysis relies on having molecular markers for specific cell types. However, for a cell type identified only by its circuit function, the process of identifying markers remains laborious. Here, we report physiological optical tagging sequencing (PhOTseq), a technique for tagging and expression-profiling cells based on their functional properties. We demonstrate that PhOTseq is capable of selecting rare cell types and enriching them by nearly one hundred-fold. We applied PhOTseq to the challenge of mapping receptor-ligand pairings among vomeronasal pheromone-sensing neurons in mice. Together with in vivo ectopic expression of vomeronasal chemoreceptors, PhOTseq identified the complete combinatorial receptor code for a specific set of ligands, and revealed that the primary sequence of a chemoreceptor was an unexpectedly strong predictor of functional similarity.

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