Chapter 6 Temporal and spatial coding in the rat vibrissal system

2001 ◽  
pp. 75-87 ◽  
Author(s):  
Ehud Ahissar ◽  
Miriam Zacksenhouse
Keyword(s):  
Spatial Coding ◽  
Temporal And Spatial ◽  
Vibrissal System

Spatial Coding of Information on Temporal Order in Short-Term Memory

1993 ◽  
Vol 76 (1) ◽  
pp. 119-124 ◽  
Author(s):  
Oliver W. Hill ◽  
Ralph W Stuckey
Keyword(s):  
Visual Field ◽  
Temporal Order ◽  
Short Term Memory ◽  
Right Visual Field ◽  
Spatial Coding ◽  
Spatial Cues ◽  
Short Term ◽  
Temporal Encoding ◽  
Temporal And Spatial ◽  
The Right

This study examined the effect of spatial cues on judgments of temporal order for digits presented to the right or left visual field. 56 subjects were better able to recall temporal order on trials with congruent temporal and spatial cues, and on trials in which stimuli were presented to the right visual field. The implications of these results for several models of temporal encoding are discussed.

scholarly journals Time interaction with two spatial dimensions: from left/right to near/far

2021 ◽  
Author(s):  
Michela Candini ◽  
Mariano D'Angelo ◽  
Francesca Frassinetti
Keyword(s):  
Tool Use ◽  
Spatial Coding ◽  
Near Space ◽  
Time Interaction ◽  
Age Related ◽  
Before And After ◽  
Spatial Dimensions ◽  
Temporal And Spatial ◽  
Healthy Participants ◽  
Temporal Judgments

We explore time and space relationship according to two spatial coding: the left/right extension and the reachability of stimulus along a near/far dimension. Four experiments were carried out in which healthy participants performed the Time and Spatial Bisection tasks in near/far space, before and after a short or long tool-use training. Stimuli were prebisected horizontal lines of different temporal durations in which the midpoint was manipulated according to Muller-Lyer illusion. The perceptual illusory effects emerged in spatial but not temporal judgments. We revealed that temporal and spatial representations dynamically change accordingly with individual’s action potentialities: temporal duration was perceived as shorter and the perceived line’s midpoint was shifted to the left in far than in near space. Crucially, this dissociation disappeared following a long but not short tool-use training. Finally, we observed age-related difference in spatial attention which may be crucial in built the memory temporal standard to categorize durations.

scholarly journals Aberrant structural synaptic dynamics precede disorganization of temporal and spatial coding in the hippocampus upon repeated stress exposure

2020 ◽  
Author(s):  
Alireza Chenani ◽  
Ghabiba Weston ◽  
Alessandro F. Ulivi ◽  
Tim P. Castello-Waldow ◽  
Alon Chen ◽  
...  
Keyword(s):  
Acute Stress ◽  
Structural Connectivity ◽  
Temporal Organization ◽  
Stressful Event ◽  
Stress Exposure ◽  
Post Traumatic Stress ◽  
Spatial Coding ◽  
Repeated Stress ◽  
Temporal And Spatial ◽  
Synaptic Dynamics

ABSTRACTStress exposure strongly contributes to the pathophysiology of psychiatric diseases such as depression, schizophrenia, anxiety, and post-traumatic stress disorder. It also affects both function and structure of hippocampal CA1, leading to episodic memory impairment. Here, we used deep-brain optical imaging to elucidate the effects of stress on CA1 pyramidal neuron structural connectivity and activity.We tracked dynamics of dendritic spines during repeated stress and found decrease in spinogenesis followed by decrease in spine stability. In contrast to repeated stress, acute stress led to stabilization of the spines born in temporal proximity to the stressful event. To investigate the link between structural plasticity and activity patterns upon repeated stress, we studied the activity of thousands of CA1 pyramidal neurons in freely-moving. We found an increase in activity and loss of temporal organization followed by a disruption in temporal and spatial coding. Our data suggest that stress-induced sustained increase in activity leads to loss of structural connectivity and subsequent temporal and spatial coding impairments.

Space and Time Distribution of Hard X-Ray Emission in a Loop at the Beginning of a Flare

1994 ◽  
Vol 144 ◽  
pp. 275-277
Author(s):  
M. Karlický ◽  
J. C. Hénoux
Keyword(s):  
Time Distribution ◽  
Electron Bombardment ◽  
Spatial Evolution ◽  
Superthermal Electrons ◽  
Flare Loop ◽  
X Ray ◽  
Superthermal Electron ◽  
Flare Loops ◽  
Chromospheric Evaporation ◽  
Temporal And Spatial

AbstractUsing a new ID hybrid model of the electron bombardment in flare loops, we study not only the evolution of densities, plasma velocities and temperatures in the loop, but also the temporal and spatial evolution of hard X-ray emission. In the present paper a continuous bombardment by electrons isotropically accelerated at the top of flare loop with a power-law injection distribution function is considered. The computations include the effects of the return-current that reduces significantly the depth of the chromospheric layer which is evaporated. The present modelling is made with superthermal electron parameters corresponding to the classical resistivity regime for an input energy flux of superthermal electrons of 109erg cm−2s−1. It was found that due to the electron bombardment the two chromospheric evaporation waves are generated at both feet of the loop and they propagate up to the top, where they collide and cause temporary density and hard X-ray enhancements.

Ultrastructural analysis of unique glycoconjugates in the rat olfactory system

1992 ◽  
Vol 50 (1) ◽  
pp. 890-891
Author(s):  
James E. Crandall ◽  
Linda C. Hassinger ◽  
Gerald A. Schwarting
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Monoclonal Antibodies ◽  
Olfactory System ◽  
Olfactory Bulbs ◽  
Temporal And Spatial Patterns ◽  
Carbohydrate Epitopes ◽  
Olfactory Systems ◽  
Temporal And Spatial ◽  
Cell Surface Glycoconjugates

Cell surface glycoconjugates are considered to play important roles in cell-cell interactions in the developing central nervous system. We have previously described a group of monoclonal antibodies that recognize defined carbohydrate epitopes and reveal unique temporal and spatial patterns of immunoreactivity in the developing main and accessory olfactory systems in rats. Antibody CC2 reacts with complex α-galactosyl and α-fucosyl glycoproteins and glycolipids. Antibody CC1 reacts with terminal N-acetyl galactosamine residues of globoside-like glycolipids. Antibody 1B2 reacts with β-galactosyl glycolipids and glycoproteins. Our light microscopic data suggest that these antigens may be located on the surfaces of axons of the vomeronasal and olfactory nerves as well as on some of their target neurons in the main and accessory olfactory bulbs.

Temporal and spatial interrelationships of confronting cisternae to nuclear envelope

1992 ◽  
Vol 50 (1) ◽  
pp. 930-931
Author(s):  
John R. Palisano
Keyword(s):  
Endoplasmic Reticulum ◽  
Nuclear Envelope ◽  
Tumor Cells ◽  
Hela Cells ◽  
Microscopic Investigation ◽  
Electron Microscopic Investigation ◽  
Serial Sections ◽  
Electron Microscopic ◽  
Fetal Rat ◽  
Temporal And Spatial

Although confronting cistemae (CC) have been observed in a variety of tumor cells and normal fetal rat, mouse, and human epithelial tissues, little is known about their origin or role in mitotic cells. While several investigators have suggested that CC arise from nuclear envelope (NE) folding back on itself during prophase, others have suggested that CC arise when fragments of NE pair with endoplasmic reticulum. An electron microscopic investigation of 0.25 um thick serial sections was undertaken to examine the origin of CC in HeLa cells.

Fate of sperm membrane in fertilized ova

1993 ◽  
Vol 51 ◽  
pp. 40-41
Author(s):  
Frank J. Longo
Keyword(s):  
Electron Microscopy ◽  
Electrical Activity ◽  
Sea Urchins ◽  
Morphological Changes ◽  
Integrated System ◽  
Electrophysiological Recording ◽  
Experimental Conditions ◽  
The Status ◽  
Sperm Membrane ◽  
Temporal And Spatial

Measurement of the egg's electrical activity, the fertilization potential or the activation current (in voltage clamped eggs), provides a means of detecting the earliest perceivable response of the egg to the fertilizing sperm. By using the electrical physiological record as a “real time” indicator of the instant of electrical continuity between the gametes, eggs can be inseminated with sperm at lower, more physiological densities, thereby assuring that only one sperm interacts with the egg. Integrating techniques of intracellular electrophysiological recording, video-imaging, and electron microscopy, we are able to identify the fertilizing sperm precisely and correlate the status of gamete organelles with the first indication (fertilization potential/activation current) of the egg's response to the attached sperm. Hence, this integrated system provides improved temporal and spatial resolution of morphological changes at the site of gamete interaction, under a variety of experimental conditions. Using these integrated techniques, we have investigated when sperm-egg plasma membrane fusion occurs in sea urchins with respect to the onset of the egg's change in electrical activity.

Specificity determinants of phosphoprotein phosphatases controlling kinetochore functions

2020 ◽  
Vol 64 (2) ◽  
pp. 325-336 ◽  
Author(s):  
Dimitriya H. Garvanska ◽  
Jakob Nilsson
Keyword(s):  
Spindle Assembly Checkpoint ◽  
Activity Level ◽  
Phosphorylation Sites ◽  
Binding Affinities ◽  
Mitotic Kinases ◽  
Anaphase Onset ◽  
Phosphoprotein Phosphatases ◽  
Linear Motifs ◽  
Temporal And Spatial ◽  
Kinetochore Function

Abstract Kinetochores are instrumental for accurate chromosome segregation by binding to microtubules in order to move chromosomes and by delaying anaphase onset through the spindle assembly checkpoint (SAC). Dynamic phosphorylation of kinetochore components is key to control these activities and is tightly regulated by temporal and spatial recruitment of kinases and phosphoprotein phosphatases (PPPs). Here we focus on PP1, PP2A-B56 and PP2A-B55, three PPPs that are important regulators of mitosis. Despite the fact that these PPPs share a very similar active site, they target unique ser/thr phosphorylation sites to control kinetochore function. Specificity is in part achieved by PPPs binding to short linear motifs (SLiMs) that guide their substrate specificity. SLiMs bind to conserved pockets on PPPs and are degenerate in nature, giving rise to a range of binding affinities. These SLiMs control the assembly of numerous substrate specifying complexes and their position and binding strength allow PPPs to target specific phosphorylation sites. In addition, the activity of PPPs is regulated by mitotic kinases and inhibitors, either directly at the activity level or through affecting PPP–SLiM interactions. Here, we discuss recent progress in understanding the regulation of PPP specificity and activity and how this controls kinetochore biology.

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