Parallel distributed network characteristics of the DSCT

1992 ◽  
Vol 68 (4) ◽  
pp. 1100-1112 ◽  
Author(s):  
C. E. Osborn ◽  
R. E. Poppele
Keyword(s):  
Time Course ◽  
Functional Organization ◽  
Activity Patterns ◽  
Three Dimensional ◽  
Principal Component ◽  
Specific Information ◽  
Distributed Network ◽  
Network Characteristics ◽  
Large Populations ◽  
Excitatory Responses

1. We examined the functional organization of the dorsal spinocerebellar tract (DSCT) and found that it is similar to that of a parallel distributed network having widespread connectivity among parallel elements. The prevailing view is that the DSCT provides receptor-specific information to the cerebellum regarding muscle and cutaneous inputs from the hindlimbs, but that view does not consider the convergent inputs to DSCT neurons from multimodal polysynaptic pathways. 2. Spontaneously active DSCT neurons respond to peripheral stimulation with changes in their firing probability. We characterized the temporal patterns of poststimulus excitability changes for a large number of neurons using principal component analysis. The response of each neuron was represented by a response vector in three-dimensional principal component space, in which similar vectors represent responses having a similar waveform for their poststimulus activity patterns. 3. We compared the responses of large populations of DSCT units to two types of stimuli: small (3-8 deg) passive rotations of the foot at the ankle of an intact limb (234 cells) and stretch or contraction of an isolated muscle group (gastrocnemius-soleus, 168 cells). Most of the cells tested had significant responses (P < 0.05) to both types of stimuli (40-78% responded to muscle stimulation and 88% to foot rotation), and they exhibited similar patterns of poststimulus activity. Long-lasting inhibitory responses and excitatory responses with a range of peak times (< 10- > 60 ms) were prevalent in all cases. The population response to each stimulus was characterized by the relative incidence of response types among the units in a representative sample of the population. 4. The time course of excitability changes induced in DSCT cells by the stimuli could have been determined primarily by the presynaptic circuitry or by postsynaptic factors intrinsic to the DSCT cells. The evidence presented suggests that the selection of response waveforms and their distribution among the DSCT cells was determined presynaptically. We found that individual cells were capable of diverse responses to different stimuli. 5. Sample groups of 7-30 cells were selected at random and also on the basis of the similarity of their responses to one type of stimulus. The distributions of response types among the cells of the sample groups were compared to the distributions for the entire population recorded for each stimulus.(ABSTRACT TRUNCATED AT 400 WORDS)

Static and dynamic postural control in long-term microgravity: evidence of a dual adaptation

2001 ◽  
Vol 90 (1) ◽  
pp. 205-215 ◽  
Author(s):  
Guido Baroni ◽  
Alessandra Pedrocchi ◽  
Giancarlo Ferrigno ◽  
Jean Massion ◽  
Antonio Pedotti
Keyword(s):  
Postural Control ◽  
Time Course ◽  
Center Of Mass ◽  
Three Dimensional ◽  
Principal Component ◽  
Movement Analysis ◽  
Trunk Flexion ◽  
Dynamic Movement ◽  
Static Body

The adaptation of dynamic movement-posture coordination during forward trunk bending was investigated in long-term weightlessness. Three-dimensional movement analysis was carried out in two astronauts during a 4-mo microgravity exposure. The principal component analysis was applied to joint-angle kinematics for the assessment of angular synergies. The anteroposterior center of mass (CM) displacement accompanying trunk flexion was also quantified. The results reveal that subjects kept typically terrestrial strategies of movement-posture coordination. The temporary disruption of joint-angular synergies observed at subjects' first in-flight session was promptly recovered when repetitive sessions in flight were analyzed. The CM anteroposterior shift was consistently <3–4 cm, suggesting that subjects could dynamically control the CM position throughout the whole flight. This is in contrast to the observed profound microgravity-induced disruption of the quasi-static body orientation and initial CM positioning. Although this study was based on only two subjects, evidence is provided that static and dynamic postural control might be under two separate mechanisms, adapting with their specific time course to the constraints of microgravity.

Components of responses of a population of DSCT neurons to muscle stretch and contraction

1989 ◽  
Vol 61 (2) ◽  
pp. 456-465 ◽  
Author(s):  
C. E. Osborn ◽  
R. E. Poppele
Keyword(s):  
Time Course ◽  
Functional Organization ◽  
Afferent Fiber ◽  
Response Probability ◽  
Principal Component ◽  
Response Patterns ◽  
Afferent Pathways ◽  
Hindlimb Muscles ◽  
Spinocerebellar Tract ◽  
And Cluster Analysis

1. Impulse activity of 264 units of the dorsal spinocerebellar tract (DSCT) was recorded during random contraction or stretch in hindlimb muscles. Contractions were evoked in either the isolated gastrocnemius-soleus (GS) muscles or the intact limb during crossed-extensor reflexes; stretches were applied to the isolated GS. 2. The time course of poststimulus changes in spike activity of DSCT neurons was determined from the response probability function (RPF; Ref. 15). These data were analyzed using principal component and cluster analysis to group the responses according to the RPF waveforms. 3. The responses to each type of stimulus displayed a remarkable similarity in time course, regardless of the type of stimulus used. The responses were also similar to those observed previously during single shock nerve stimulation (14). 4. The most reasonable explanation for these results is that the time course of excitability changes in DSCT neurons is determined less by particular types of receptors or patterns of afferent fiber activity than by the circuitry and afferent pathways impinging on the neurons of the DSCT. 5. The functional organization of DSCT suggested by these results includes a wide divergence from sensory receptors along polysynaptic pathways to DSCT neurons and considerable convergence onto each neuron from a diversity of receptors. Individual DSCT cells may respond to stimuli with one of a few stereo-typical response patterns yet the distribution of those patterns among the units of the DSCT population may be unique for each stimulus.

scholarly journals Stimulation-specific information is represented as local activity patterns across the brain

2019 ◽  
Author(s):  
Amirouche Sadoun ◽  
Tushar Chauhan ◽  
Samir Mameri ◽  
Yifan Zhang ◽  
Pascal Barone ◽  
...  
Keyword(s):  
Brain Activity ◽  
Activity Patterns ◽  
Three Dimensional ◽  
Correlation Method ◽  
Brain Regions ◽  
Specific Information ◽  
Spatially Correlated ◽  
Face Area ◽  
Spatial Configurations ◽  
The Brain

AbstractModern neuroimaging represents three-dimensional brain activity, which varies across brain regions. It remains unknown whether activity within brain regions is organized in spatial configurations to reflect perceptual and cognitive processes. We developed a rotational cross-correlation method allowing a straightforward analysis of spatial activity patterns for the precise detection of the spatially correlated distributions of brain activity. Using several statistical approaches, we found that the seed patterns in the fusiform face area were robustly correlated to brain regions involved in face-specific representations. These regions differed from the non-specific visual network meaning that activity structure in the brain is locally preserved in stimulation-specific regions. Our findings indicate spatially correlated perceptual representations in cerebral activity and suggest that the 3D coding of the processed information is organized in locally preserved activity patterns. More generally, our results provide the first demonstration that information is represented and transmitted as local spatial configurations of brain activity.

Predicting spatial activity patterns in a neural map from a probabilistic atlas of 3-D reconstructed neurons

1995 ◽  
Vol 53 ◽  
pp. 812-813
Author(s):  
G. Jacobs ◽  
F. Theunissen
Keyword(s):  
Activity Patterns ◽  
Three Dimensional ◽  
Sensory System ◽  
Neural System ◽  
Probabilistic Atlas ◽  
Uniform Sample ◽  
Dimensional Reconstruction ◽  
The Time Domain ◽  
And Function ◽  
Visualization Techniques

In order to understand how the algorithms underlying neural computation are implemented within any neural system, it is necessary to understand details of the anatomy, physiology and global organization of the neurons from which the system is constructed. Information is represented in neural systems by patterns of activity that vary in both their spatial extent and in the time domain. One of the great challenges to microscopists is to devise methods for imaging these patterns of activity and to correlate them with the underlying neuroanatomy and physiology. We have addressed this problem by using a combination of three dimensional reconstruction techniques, quantitative analysis and computer visualization techniques to build a probabilistic atlas of a neural map in an insect sensory system. The principal goal of this study was to derive a quantitative representation of the map, based on a uniform sample of afferents that was of sufficient size to allow statistically meaningful analyses of the relationships between structure and function.

A Study on Utilization of Three-Dimensional Sensor Lip Image for Developing a Pronunciation Recognition System

2019 ◽  
Vol 63 (5) ◽  
pp. 50402-1-50402-9 ◽  
Author(s):  
Ing-Jr Ding ◽  
Chong-Min Ruan
Keyword(s):  
Principal Component Analysis ◽  
Automatic Speech Recognition ◽  
Feature Fusion ◽  
Three Dimensional ◽  
Principal Component ◽  
Recognition System ◽  
Geometrical Characteristics ◽  
3D Geometry ◽  
Different Types ◽  
The Disabled

Abstract The acoustic-based automatic speech recognition (ASR) technique has been a matured technique and widely seen to be used in numerous applications. However, acoustic-based ASR will not maintain a standard performance for the disabled group with an abnormal face, that is atypical eye or mouth geometrical characteristics. For governing this problem, this article develops a three-dimensional (3D) sensor lip image based pronunciation recognition system where the 3D sensor is efficiently used to acquire the action variations of the lip shapes of the pronunciation action from a speaker. In this work, two different types of 3D lip features for pronunciation recognition are presented, 3D-(x, y, z) coordinate lip feature and 3D geometry lip feature parameters. For the 3D-(x, y, z) coordinate lip feature design, 18 location points, each of which has 3D-sized coordinates, around the outer and inner lips are properly defined. In the design of 3D geometry lip features, eight types of features considering the geometrical space characteristics of the inner lip are developed. In addition, feature fusion to combine both 3D-(x, y, z) coordinate and 3D geometry lip features is further considered. The presented 3D sensor lip image based feature evaluated the performance and effectiveness using the principal component analysis based classification calculation approach. Experimental results on pronunciation recognition of two different datasets, Mandarin syllables and Mandarin phrases, demonstrate the competitive performance of the presented 3D sensor lip image based pronunciation recognition system.

Time Series Analysis of Transmesothelial Invasion by Endometrial Stromal and Epithelial Cells Using Three-dimensional Confocal Microscopy

2001 ◽  
Vol 7 (S2) ◽  
pp. 580-581
Author(s):  
CA Witz ◽  
S Cho ◽  
VE Centonze ◽  
IA Montoya-Rodriguez ◽  
RS Schenken
Keyword(s):  
Epithelial Cells ◽  
Stromal Cells ◽  
Time Course ◽  
Three Dimensional ◽  
Collagen Iv ◽  
Mesothelial Cells ◽  
Endometrial Stromal Cells ◽  
Human Collagen ◽  
Endometrial Epithelial Cells

Using human peritoneal explants, we have previously demonstrated that endometrial stromal cells (ESCs) and endometrial epithelial cells (EECs) attach to intact mesothelium. Attachment occurs within one hour and mesothelial invasion occurs within 18 hours (Figure 1). We have also demonstrated that, in vivo, the mesothelium overlies a continuous layer of collagen IV (Col IV).More recently we have used CLSM, to study the mechanism and time course of ESC and EEC attachment and invasion through mesothelial monolayers. in these studies, CellTracker® dyes were used to label cells. Mesothelial cells were labeled with chloromethylbenzoylaminotetramethylrhodamine (CellTracker Orange). Mesothelial cells were then plated on human collagen IV coated, laser etched coverslips. Mesothelial cells were cultured to subconfluence. ESCs and EECs, labeled with chloromethylfluorscein diacetate (CellTracker Green) were plated on the mesothelial monolayers. Cultures were examined at 1, 6, 12 and 24 hours with simultaneous differential interference contrast and CLSM.

scholarly journals Elastic transformation of histological slices allows precise co-registration with microCT data sets for a refined virtual histology approach

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jonas Albers ◽  
Angelika Svetlove ◽  
Justus Alves ◽  
Alexander Kraupner ◽  
Francesca di Lillo ◽  
...  
Keyword(s):  
Three Dimensional ◽  
High Specificity ◽  
Histopathological Analysis ◽  
Specific Information ◽  
Data Sets ◽  
Virtual Histology ◽  
Novel Approach ◽  
Cell Tissue ◽  
Immuno Histochemistry ◽  
3D Information

AbstractAlthough X-ray based 3D virtual histology is an emerging tool for the analysis of biological tissue, it falls short in terms of specificity when compared to conventional histology. Thus, the aim was to establish a novel approach that combines 3D information provided by microCT with high specificity that only (immuno-)histochemistry can offer. For this purpose, we developed a software frontend, which utilises an elastic transformation technique to accurately co-register various histological and immunohistochemical stainings with free propagation phase contrast synchrotron radiation microCT. We demonstrate that the precision of the overlay of both imaging modalities is significantly improved by performing our elastic registration workflow, as evidenced by calculation of the displacement index. To illustrate the need for an elastic co-registration approach we examined specimens from a mouse model of breast cancer with injected metal-based nanoparticles. Using the elastic transformation pipeline, we were able to co-localise the nanoparticles to specifically stained cells or tissue structures into their three-dimensional anatomical context. Additionally, we performed a semi-automated tissue structure and cell classification. This workflow provides new insights on histopathological analysis by combining CT specific three-dimensional information with cell/tissue specific information provided by classical histology.

scholarly journals A Proof-of-Concept Algorithm for the Retrieval of Total Column Amount of Trace Gases in a Multi-Dimensional Atmosphere

2021 ◽  
Vol 13 (2) ◽  
pp. 270
Author(s):  
Adrian Doicu ◽  
Dmitry S. Efremenko ◽  
Thomas Trautmann
Keyword(s):  
Trace Gases ◽  
Three Dimensional ◽  
Principal Component ◽  
Radiative Transfer Model ◽  
Computational Time ◽  
Transfer Model ◽  
Proof Of Concept ◽  
Discrete Ordinate ◽  
Distribution Method ◽  
Total Column

An algorithm for the retrieval of total column amount of trace gases in a multi-dimensional atmosphere is designed. The algorithm uses (i) certain differential radiance models with internal and external closures as inversion models, (ii) the iteratively regularized Gauss–Newton method as a regularization tool, and (iii) the spherical harmonics discrete ordinate method (SHDOM) as linearized radiative transfer model. For efficiency reasons, SHDOM is equipped with a spectral acceleration approach that combines the correlated k-distribution method with the principal component analysis. The algorithm is used to retrieve the total column amount of nitrogen for two- and three-dimensional cloudy scenes. Although for three-dimensional geometries, the computational time is high, the main concepts of the algorithm are correct and the retrieval results are accurate.

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