scholarly journals Entorhinal-retrosplenial circuits for allocentric-egocentric transformation of boundary coding

eLife ◽  
2020 ◽  
Vol 9 ◽  
Author(s):  
Joeri BG van Wijngaarden ◽  
Susanne S Babl ◽  
Hiroshi T Ito

Spatial navigation requires landmark coding from two perspectives, relying on viewpoint-invariant and self-referenced representations. The brain encodes information within each reference frame but their interactions and functional dependency remains unclear. Here we investigate the relationship between neurons in the rat's retrosplenial cortex (RSC) and entorhinal cortex (MEC) that increase firing near boundaries of space. Border cells in RSC specifically encode walls, but not objects, and are sensitive to the animal’s direction to nearby borders. These egocentric representations are generated independent of visual or whisker sensation but are affected by inputs from MEC that contains allocentric spatial cells. Pharmaco- and optogenetic inhibition of MEC led to a disruption of border coding in RSC, but not vice versa, indicating allocentric-to-egocentric transformation. Finally, RSC border cells fire prospective to the animal’s next motion, unlike those in MEC, revealing the MEC-RSC pathway as an extended border coding circuit that implements coordinate transformation to guide navigation behavior.

2019 ◽  
Author(s):  
Joeri B.G. van Wijngaarden ◽  
Susanne S. Babl ◽  
Hiroshi T. Ito

AbstractBorders and edges are salient and behaviourally relevant features for navigating the environment. The brain forms dedicated neural representations of environmental boundaries, which are assumed to serve as a reference for spatial coding. Here we expand this border coding network to include the retrosplenial cortex (RSC) in which we identified neurons that increase their firing near all boundaries of an arena. RSC border cells specifically encode walls, but not objects, and maintain their tuning in the absence of direct sensory detection. Unlike border cells in the medial entorhinal cortex (MEC), RSC border cells are sensitive to the animal’s direction to nearby walls located contralateral to the recorded hemisphere. Pharmacogenetic inactivation of MEC led to a disruption of RSC border coding, but not vice versa, indicating network directionality. Together these data shed light on how information about distance and direction of boundaries is generated in the brain for guiding navigation behaviour.


Science ◽  
2008 ◽  
Vol 322 (5909) ◽  
pp. 1865-1868 ◽  
Author(s):  
Trygve Solstad ◽  
Charlotte N. Boccara ◽  
Emilio Kropff ◽  
May-Britt Moser ◽  
Edvard I. Moser

We report the existence of an entorhinal cell type that fires when an animal is close to the borders of the proximal environment. The orientation-specific edge-apposing activity of these “border cells” is maintained when the environment is stretched and during testing in enclosures of different size and shape in different rooms. Border cells are relatively sparse, making up less than 10% of the local cell population, but can be found in all layers of the medial entorhinal cortex as well as the adjacent parasubiculum, often intermingled with head-direction cells and grid cells. Border cells may be instrumental in planning trajectories and anchoring grid fields and place fields to a geometric reference frame.


2020 ◽  
Author(s):  
Hyuk-June Moon ◽  
Baptiste Gauthier ◽  
Hyeong-Dong Park ◽  
Nathan Faivre ◽  
Olaf Blanke

AbstractGrid cells in entorhinal cortex (EC) encode an individual’s location in space and rely on environmental cues and self-motion cues derived from the individual’s body. Body-derived signals are also primary signals for the sense of self as located in space (i.e. bodily self-consciousness, BSC). However, it is currently unknown whether BSC impacts grid cell activity and how such changes relate to experimental modulations of BSC. Integrating BSC with a spatial navigation task and an fMRI measure to detect grid cell-like representation (GCLR) in humans, we report a robust GCLR modulation in EC when participants navigated during an enhanced BSC state. These changes were further associated with improved spatial navigation performance and increased activity in posterior parietal and retrosplenial cortex. These data link entorhinal grid cell activity with BSC and show that BSC modulates ego-versus allocentric spatial processes about an individual’s location in space in a distributed spatial navigation system.


2010 ◽  
Vol 2010 (1) ◽  
pp. 5-22
Author(s):  
Ralf Becker

The article examines the relationship between freedom, guilt and responsibility in Dostojewski’s and Sartre’s works. Both attribute a great measure of personal freedom to man. Therefore, they do not tolerate excuses. Whoever is free, carries responsibility and gets caught up in guilt. Dostojewski’s focus is mainly on guilt, Sartre’s is on responsibility. They share the conviction that we can delegate responsibility for our actions or our way of living neither to a whole, of which we are a part, like society (the ,milieu'), nor to a part, for which we are the whole, like the ,brain' or the ,genes'. In that sense, Dostojewski’s and Sartre’s attempts at an ethic of responsibility also offer convincing arguments against determinism.


Author(s):  
M.P. Sutunkova ◽  
B.A. Katsnelson ◽  
L.I. Privalova ◽  
S.N. Solovjeva ◽  
V.B. Gurvich ◽  
...  

We conducted a comparative assessment of the nickel oxide nanoparticles toxicity (NiO) of two sizes (11 and 25 nm) according to a number of indicators of the body state after repeated intraperitoneal injections of these particles suspensions. At equal mass doses, NiO nanoparticles have been found to cause various manifestations of systemic subchronic toxicity with a particularly pronounced effect on liver, kidney function, the body’s antioxidant system, lipid metabolism, white and red blood, redox metabolism, spleen damage, and some disorders of nervous activity allegedly related to the possibility of nickel penetration into the brain from the blood. The relationship between the diameter and toxicity of particles is ambiguous, which may be due to differences in toxicokinetics, which is controlled by both physiological mechanisms and direct penetration of nanoparticles through biological barriers and, finally, unequal solubility.


2020 ◽  
Vol 21 (9) ◽  
pp. 649-660
Author(s):  
Subashini Raman ◽  
Syed Mahmood ◽  
Ayah R. Hilles ◽  
Md Noushad Javed ◽  
Motia Azmana ◽  
...  

Background: Blood-brain barrier (BBB) plays a most hindering role in drug delivery to the brain. Recent research comes out with the nanoparticles approach, is continuously working towards improving the delivery to the brain. Currently, polymeric nanoparticle is extensively involved in many therapies for spatial and temporal targeted areas delivery. Methods: We did a non-systematic review, and the literature was searched in Google, Science Direct and PubMed. An overview is provided for the formulation of polymeric nanoparticles using different methods, effect of surface modification on the nanoparticle properties with types of polymeric nanoparticles and preparation methods. An account of different nanomedicine employed with therapeutic agent to cross the BBB alone with biodistribution of the drugs. Results: We found that various types of polymeric nanoparticle systems are available and they prosper in delivering the therapeutic amount of the drug to the targeted area. The effect of physicochemical properties on nanoformulation includes change in their size, shape, elasticity, surface charge and hydrophobicity. Surface modification of polymers or nanocarriers is also vital in the formulation of nanoparticles to enhance targeting efficiency to the brain. Conclusion: More standardized methods for the preparation of nanoparticles and to assess the relationship of surface modification on drug delivery. While the preparation and its output like drug loading, particle size, and charge, permeation is always conflicted, so it requires more attention for the acceptance of nanoparticles for brain delivery.


2021 ◽  
Vol 190 ◽  
pp. 553-559
Author(s):  
Irina K. Malashenkova ◽  
Vadim L. Ushakov ◽  
Sergey A. Krynskiy ◽  
Daniil P. Ogurtsov ◽  
Nikita A. Khailov ◽  
...  

Neurology ◽  
2018 ◽  
Vol 91 (23 Supplement 1) ◽  
pp. S17.1-S17
Author(s):  
Haruo Nakayama ◽  
Yu Hiramoto ◽  
Yuriko Numata ◽  
Satoshi Fujita ◽  
Nozomi Hirai ◽  
...  

ObjectiveTo evaluate the relationship between functional anisotropy (FA) and neuropsychological evaluation in concussion.MethodsDiffusion tensor MRI included FA of the Brain and neuropsychological evaluation were conducted on 10 patients with concussion who were diagnosed from April 2017 to March 2018. FA was extracted from 2 regions of interest in Corpus callosum (CC) and corticospinal tract (CT). Detailed neuropsychological testing with an emphasis on Working memory (WM) and Processing speed (PS) was also conducted. The FA value in that 2 regions were compared between the 2 groups of 5 patients (group F) who failed either in WM or PS and 5 cases (group NF) who did not admit it.ResultsMean FA values in CC and CT in the Group F were 0.70 and 0.52. Mean FA values in CC and CT in the Group NF were 0.48 and 0.55.ConclusionsOur result suggests that the FA value of CC did not explain the significant fluctuation of the neuropsychological function. However, FA value in CT were shown to explain the fluctuation of WM and PS.


Author(s):  
James Deery

AbstractFor some, the states and processes involved in the realisation of phenomenal consciousness are not confined to within the organismic boundaries of the experiencing subject. Instead, the sub-personal basis of perceptual experience can, and does, extend beyond the brain and body to implicate environmental elements through one’s interaction with the world. These claims are met by proponents of predictive processing, who propose that perception and imagination should be understood as a product of the same internal mechanisms. On this view, as visually imagining is not considered to be world-involving, it is assumed that world-involvement must not be essential for perception, and thus internalism about the sub-personal basis is true. However, the argument for internalism from the unity of perception and imagination relies for its strength on a questionable conception of the relationship between the two experiential states. I argue that proponents of the predictive approach are guilty of harbouring an implicit commitment to the common kind assumption which does not follow trivially from their framework. That is, the assumption that perception and imagination are of the same fundamental kind of mental event. I will argue that there are plausible alternative ways of conceiving of this relationship without drawing internalist metaphysical conclusions from their psychological theory. Thus, the internalist owes the debate clarification of this relationship and further argumentation to secure their position.


2014 ◽  
Vol 67 (1) ◽  
Author(s):  
Farahwahida Mohd Yusof ◽  
Siti Norlina Muhamad ◽  
Arieff Salleh Rosman ◽  
Sarimah Noor Ahmad ◽  
Nor Farhah Razak ◽  
...  

This article discusses the phenomenon of sleep, with emphasized to its importance, sleeping times, sleeping positions and even the etiquette of sleeping, from the views of Islam and Science. The Quran and Science are inseparable and the relationship between the two is highly balanced. Scientists have said that the phenomena of sleep is a miracle that deserves to be analysed and studied in depth, as it is a complex phenomena. Glory and Praise to be Allah Almighty has decreed in the Quran of the importance of sleep in the day and night, and that sleep is one of the signs of Allah’s Almighty power and is a miracle to be studied by each individual. Islam places great importance on taking care of one’s body and sleep is one need that has to be fulfilled. Scientists have stressed that sleep is needed to rest the brain, improve memory, and increase one’s energy. This shows that Islam places great importance on having productivity and alertness in each individual’s deed. Many scientific facts that had been clearly stated in a fundamental manner in the Quran could only be analysed with the advanced technology of the 20th century. These facts were not known when they were first revealed and are proof that the Quran is the book of Allah Almighty. The view of Islam on the sleep phenomenon is in line with and is according to the findings of contemporary scien


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