scholarly journals Neural Circuits and Some New Factors Involved in Hippocampal Memory

2022 ◽  
Author(s):  
Ruiying Jing ◽  
Qiujie Cai ◽  
Wen Li ◽  
Xinhua Zhang

Humans and other primates have memory, and the hippocampus plays a critical role in this process. The neural circuitry is one of the structural foundations for the hippocampus in exerting memory function. To understand the relationship between the hippocampus and memory, we need to understand neural circuits. Past research has identified several classical neural circuits involved in memory. Although there are challenges with the study of hippocampal neural circuits, research on this topic has continued, and some progress has been made. Here, we discuss recent advances in our understanding of hippocampal neural circuit mechanisms and some of the newly discovered factors that affect memory. Substantial progress has been made regarding hippocampal memory circuits and Alzheimer’s disease. However, it is unclear whether these novel findings regarding hippocampal memory circuits hold promise for human memory studies. Additional research on this topic is needed.

2018 ◽  
Author(s):  
M.J. Spriggs ◽  
C.S. Thompson ◽  
D Moreau ◽  
N.A. McNair ◽  
C.C. Wu ◽  
...  

BackgroundLong-Term Potentiation (LTP) is recognised as a core neuronal process underlying long-term memory. However, a direct relationship between LTP and human memory performance is yet to be demonstrated. The first aim of the current study was thus to assess the relationship between LTP and human long-term memory performance. With this also comes an opportunity to explore factors thought to mediate the relationship between LTP and long-term memory, and to gain additional insight into variations in memory function and memory decline. The second aim of the current study was to explore the relationship between LTP and memory in groups differing with respect to BDNF Val66Met; a single nucleotide polymorphism implicated in memory function.Methods28 participants (15 female) were split into three genotype groups (Val/Val, Val/Met, Met/Met) and were presented with both an EEG paradigm for inducing LTP-like enhancements of the visually-evoked response, and a test of visual memory.ResultsThe magnitude of LTP 40 minutes after induction was predictive of long-term memory performance. Additionally, the BDNF Met allele was associated with both reduced LTP and reduced memory performance.ConclusionsThe current study not only presents the first evidence for a relationship between sensory LTP and human memory performance, but also demonstrates how targeting this relationship can provide insight into factors implicated in variation in human memory performance. It is anticipated that this will be of utility to future clinical studies of disrupted memory function.


2004 ◽  
Vol 16 (8) ◽  
pp. 1412-1425 ◽  
Author(s):  
Eric I. Knudsen

Experience exerts a profound influence on the brain and, therefore, on behavior. When the effect of experience on the brain is particularly strong during a limited period in development, this period is referred to as a sensitive period. Such periods allow experience to instruct neural circuits to process or represent information in a way that is adaptive for the individual. When experience provides information that is essential for normal development and alters performance permanently, such sensitive periods are referred to as critical periods. Although sensitive periods are reflected in behavior, they are actually a property of neural circuits. Mechanisms of plasticity at the circuit level are discussed that have been shown to operate during sensitive periods. A hypothesis is proposed that experience during a sensitive period modifies the architecture of a circuit in fundamental ways, causing certain patterns of connectivity to become highly stable and, therefore, energetically preferred. Plasticity that occurs beyond the end of a sensitive period, which is substantial in many circuits, alters connectivity patterns within the architectural constraints established during the sensitive period. Preferences in a circuit that result from experience during sensitive periods are illustrated graphically as changes in a “stability landscape,” a metaphor that represents the relative contributions of genetic and experiential influences in shaping the information processing capabilities of a neural circuit. By understanding sensitive periods at the circuit level, as well as understanding the relationship between circuit properties and behavior, we gain a deeper insight into the critical role that experience plays in shaping the development of the brain and behavior.


2020 ◽  
Author(s):  
Ju Yang ◽  
Nicola Mandriota ◽  
Steven Glenn Harrellson ◽  
John Anthony Jones-Molina ◽  
Rafael Yuste ◽  
...  

AbstractSynapses play a critical role in neural circuits, and they are potential sites for learning and memory. Maintenance of synaptic adhesion is critical for neural circuit function, however, biophysical mechanisms that help maintain synaptic adhesion are not clear. Studies with various cell types demonstrated the important role of stiffness in cellular adhesions. Although synaptic stiffness could also play a role in synaptic adhesion, stiffnesses of synapses are difficult to characterize due to their small size and challenges in verifying synapse identity and function. To address these challenges, we have developed an experimental platform that combines atomic force microscopy, fluorescence microscopy, and transmission electron microscopy. Here, using this platform, we report that functional, mature, excitatory synapses had an average elastic modulus of approximately 200 kPa, two orders of magnitude larger than that of the brain tissue, suggesting stiffness might have a role in synapse function. Similar to various functional and anatomical features of neural circuits, synaptic stiffness had a lognormal-like distribution, hinting a possible regulation of stiffness by processes involved in neural circuit function. In further support of this possibility, we observed that synaptic stiffness was correlated with spine size, a quantity known to correlate with synaptic strength. Using established stages of the long-term potentiation timeline and theoretical models of adhesion cluster dynamics, we developed a biophysical model of the synapse that not only explains extreme stiffness of synapses, their statistical distribution, and correlation with spine size, but also offers an explanation to how early biomolecular and structural changes during functional potentiation could lead to strengthening of synaptic adhesion. According to this model, synaptic stiffness serves as an indispensable physical messenger, feeding information back to synaptic adhesion molecules to facilitate maintenance of synaptic adhesion.


2020 ◽  
Vol 26 ◽  
Author(s):  
Yujie Shen ◽  
Yexiang Lin ◽  
Kai Liu ◽  
Jinlan Chen ◽  
Juanjuan Zhong ◽  
...  

Background: A number of studies have proposed that lncRNA XIST plays a role in the development and chemosensitivity of NSCLC. Besides, XIST may become a potential therapeutic target for NSCLC patients. The aim of this review is to reveal the biological functions and exact mechanisms of XIST in NSCLC. Methods: In this review, relevant researches involving in the relationship between XIST and NSCLC are collected through systematic retrieval of PubMed Results: XIST is an oncogene in NSCLC and is abnormally upregulated in NSCLC tissues. Considerable evidence has shown that XIST exerts a critical role in the proliferation, invasion, migration, apoptosis and chemosensitivity of NSCLC cells. XIST mainly functions as a ceRNA in NSCLC process, while XIST also functions at transcriptional levels. Conclusion: LncRNA XIST has potential to become a novel biomolecular marker of NSCLC and a therapeutic target for NSCLC.


2021 ◽  
Vol 13 (11) ◽  
pp. 5869
Author(s):  
Athanasios Krystallis ◽  
Vlad Zaharia ◽  
Antonis Zairis

Responding to the appeal for more research on the contingencies that shape the relationship between CSR and corporate performance, this paper incorporates environmental CSR, sets up an experimental survey and employs multiple mediation analysis with the aim to test the mediating role of consumer attributions on the CSR elements–consumer responses relationship; and further to examine the degree to which attributions are controllable, i.e., specific CSR elements activate specific type of attributions. Results support that attributions have a strong predicting power on consumer outcomes. The right time of appearance and the appropriate amount of resources committed to a CSR campaign, through the dual type of attributions they activate (more positive, i.e., values-driven and less negative, i.e., egoistic), impact positively on consumer reactions. In this respect, the study adds to past research showing that attributions are controllable, i.e., specific CSR initiative characteristics of a impact on the dimensionality of attributions and, through that, on specific target-types of consumer responses. This study thus shows that the activation of a dual-level attributions’ system is ambivalent, dependent on the character of the CSR campaign. The fact that specific CSR elements (i.e., CSR Timing) activate dual-level CSR motives that act complementarily indicates that managers should be clear about the capabilities of the elements of their CSR initiatives and how much impact they expect those elements to have on consumer response.


2021 ◽  
pp. 194855062199686
Author(s):  
Anita Schmalor ◽  
Steven J. Heine

Economic inequality has been associated with a host of social ills, but most research has focused on objective measures of inequality. We argue that economic inequality also has a subjective component, and understanding the effects of economic inequality will be deepened by considering the ways that people perceive inequality. In an American sample ( N = 1,014), we find that some of the key variables that past research has found to correlate with objective inequality also correlate with a subjective measure of inequality. Across six countries ( N = 683), we find that the relationship between subjective inequality and different psychological variables varies by country. Subjective inequality shows only modest correlations with objective inequality and varies by sociodemographic background.


Author(s):  
Cordelia Estevez-Casellas ◽  
Mª Dolores Gómez-Medina ◽  
Esther Sitges

Emotional intelligence plays a critical role in adolescence since it involves a change towards psychological, social, and sexual maturity; a stage in which the foundations of intimate social relationships are established. Emotional competences regulate the quality of these relationships in adolescence and can provide protection against or facilitate the use of violence within them. Based on the above, this study aims to analyze the relationship between emotional intelligence and violence exercised, received, and perceived by adolescents in dating relationships. A sample of 254 subjects (43.1% men and 56.9% women) between 12 and 18 years old was analyzed through the Emotional Intelligence Questionnaires of BarOn ICE:NA and Violence Exercised Perceived and Received by Adolescents VERA. The results of the research have shown that there is a significant and inverse relation between the dimensions of emotional intelligence and the violence exercised by adolescents in their dating relationships, and a positive and significant relation between emotional intelligence and the perception of violent behavior. For this reason, the importance of educating people about emotional intelligence from childhood within both the academic and family sphere is highlighted. This is fundamental to preventing the appearance of such violent behaviors and promoting an adequate adaptation to the environment.


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Hao-Nan Guo ◽  
Li-Xia Wang ◽  
Hong-Tao Liu

Abstract This study aims to investigate the relationship between key physicochemical parameters related to composting process and bioavailability of Cd, As and Cr during swine manure composting through regulating different initial carbon to nitrogen (C/N) ratios (15:1, 20:1, 25:1) and bulking agent types (straw, green waste). Results showed that higher initial C/N ratio of 20:1 or 25:1 and straw as bulking agent were optimal to reduce the bioavailability of Cd, As and Cr (62.4%, 20.6% and 32.2% reduction, respectively). Redundancy analysis implied that the bioavailability of Cd was significantly associated with total phosphorus and total nitrogen, deducing the formation of phosphate precipitation and biosorption might participated in the reaction process, while that of As and Cr were mainly influenced by organic matter (OM), cation exchange capacity (CEC) and OM, CEC, electric conductivity, respectively. A total of 48.5%, 64.6% and 62.2% of Cd, As and Cr redistribution information could be explained by the above parameters. Further correlation analysis revealed that bioavailable As and Cr were negatively correlated with humic acid to fulvic acid ratio. In summary, this study confirms that the mechanisms of phosphate precipitation, biosorption and humification played critical role in reducing Cd, As and Cr bioavailability during swine manure composting.


2019 ◽  
pp. 135910531986997 ◽  
Author(s):  
Huazhan Yin ◽  
Li Zhang ◽  
Dan Li ◽  
Lu Xiao ◽  
Mei Cheng

This study investigated the neuroanatomical basis of the association between depression/anxiety and sleep quality among 370 college students. The results showed that there was a significant correlation between sleep quality and depression/anxiety. Moreover, mediation results showed that the gray matter volume of the right insula mediated the relationship between depression/anxiety and sleep quality, which suggested that depression/anxiety may affect sleep quality through the right insula volume. These findings confirmed a strong link between sleep quality and depression/anxiety, while highlighting the volumetric variation in the right insula associated with emotional processing, which may play a critical role in improving sleep quality.


2005 ◽  
Vol 288 (5) ◽  
pp. R1396-R1410 ◽  
Author(s):  
Shaun W. Phillips ◽  
Gerard L. Gebber ◽  
Susan M. Barman

We used spectral analysis and event-triggered averaging to determine the effects of chemical inactivation of the medullary lateral tegmental field (LTF) on 1) the relationship of intratracheal pressure (ITP, an index of vagal lung inflation afferent activity) to sympathetic nerve discharge (SND) and phrenic nerve activity (PNA) and 2) central respiratory rate in paralyzed, artificially ventilated dial-urethane-anesthetized cats. ITP-SND coherence value at the frequency of artificial ventilation was significantly ( P < 0.05; n = 18) reduced from 0.73 ± 0.04 (mean ± SE) to 0.24 ± 0.04 after bilateral microinjection of muscimol into the LTF. Central respiratory rate was unexpectedly increased in 12 of these experiments (0.28 ± 0.03 vs. 0.95 ± 0.25 Hz). The ITP-PNA coherence value was variably affected by chemical inactivation of the LTF. It was unchanged when central respiratory rate was also not altered, decreased when respiratory rate was increased above the rate of artificial ventilation, and increased when respiratory rate was raised from a value below the rate of artificial ventilation to the same frequency as the ventilator. Chemical inactivation of the LTF increased central respiratory rate in four of six vagotomized cats but did not significantly affect the PNA-SND coherence value. These data demonstrate that the LTF 1) plays a critical role in mediating the effects of vagal lung inflation afferents on SND but not PNA, 2) helps maintain central respiratory rate in the physiological range, but 3) is not involved in the coupling of central respiratory and sympathetic circuits.


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