scholarly journals Nociceptive Craniofacial Muscle Primary Afferent Neurons Synapse in Both the Rostral and Caudal Brain Stem

2007 ◽  
Vol 98 (1) ◽  
pp. 214-223 ◽  
Author(s):  
Dean Dessem ◽  
Masayuki Moritani ◽  
Ranjinidevi Ambalavanar
Keyword(s):  
Brain Stem ◽  
Three Dimensional ◽  
Field Testing ◽  
Intracellular Recordings ◽  
Afferent Neurons ◽  
Limited Information ◽  
Muscle Stretching ◽  
Axon Collaterals ◽  
Somatosensory Information ◽  
Muscle Afferent

Limited information is available on muscle afferent neurons with fine fibers despite their presumed participation in musculoskeletal disorders, including temporomandibular disorders. To study these neurons, intracellular recordings were made from the central axons of slowly conducting muscle afferent neurons in anesthetized rats. After intraaxonal impalement, axons were characterized by masseter nerve stimulation, receptive field testing, muscle stretching and intramuscular injection of hypertonic saline. Intracellular recordings were made from 310 axons (conduction velocity: 6.5–60M/s, mean = 27.3M/s; following frequency: 27–250 Hz, mean = 110Hz). No neurons responded to cutaneous palpation or muscle stretching. Some axons ( n = 34) were intracellularly stained with biotinamide. These neurons were classified as group II/III noxious mechanoreceptors because their mechanical threshold exceeded 15 mN, and conduction velocities ranged from 12 to 40.2M/s (mean = 25.3M/s). Two morphological types were recognized by using an object-based, three-dimensional colocalization methodology to locate synapses. One type (IIIHTMVp-Vc) possessed axon collaterals that emerged along the entire main axon and synapsed in the trigeminal principal sensory nucleus and spinal trigeminal subnuclei oralis (Vo), interpolaris (Vi), and caudalis (Vc). A second type (IIIHTMVo-Vc) possessed axon collaterals that synapsed only in caudal Vo, Vi, and Vc. Our previous studies show that muscle spindle afferent neurons are activated by innocuous stimuli and synapse in the rostral and caudal brain stem; here we demonstrate that nociceptive muscle mechanoreceptor afferent axons also synapse in rostral and caudal brain stem regions. Traditional dogma asserts that the most rostral trigeminal sensory complex exclusively processes innocuous somatosensory information, whereas caudal portions receive nociceptive sensory input; the data reported here do not support this paradigm.

Three-dimensional computer-aided analysis of the intraganglionic topography of primary muscle afferent neurons in the rat

1990 ◽  
Vol 227 (4) ◽  
pp. 405-417 ◽  
Author(s):  
Jean-Marie Peyronnard ◽  
Jean-Pierre Messier ◽  
Martin Dubreuil ◽  
Louise Charron ◽  
France Lebel
Keyword(s):  
Three Dimensional ◽  
Afferent Neurons ◽  
Computer Aided Analysis ◽  
Computer Aided ◽  
Muscle Afferent

Opening and closure of Iranian back-arc basins: A seismic tomography view

2021 ◽  
Author(s):  
Nalan Lom ◽  
Abdul Qayyum ◽  
Derya Gürer ◽  
Douwe G. van der Meer ◽  
Wim Spakman ◽  
...  
Keyword(s):  
Seismic Tomography ◽  
Subduction Zones ◽  
Three Dimensional ◽  
Plate Motion ◽  
Limited Information ◽  
Three Dimensional Model ◽  
Slab Geometry ◽  
Novel Approach ◽  
Sanandaj Sirjan Zone ◽  
Back Arc

<p>Iran is a mosaic of continental blocks that are surrounded by Tethyan oceanic relics. Remnants of these oceanic rock assemblages are exposed around the Central Iranian Microcontinent (CIM), discretely along the Sanandaj-Sirjan Zone and in Jaz-Murian. The ophiolite belts surrounding the CIM are mainly assumed to represent narrow back-arc basins that opened in Cretaceous and closed before the Eocene. Although these ophiolites are exposed as small pieces on continental crust today, they represent oceans wide enough to form supra-subduction ophiolites and arc-related magmatic rocks which suggest that their palaeogeographic width was at least some hundreds of kilometers. Current models for the palaeogeographic dimension, opening and closure of these basins are highly schematic. They usually seem plausible in two-dimensional reconstructions, however a single three-dimensional model explaining whole Iran and its surrounding regions has not been fully accomplished.  This is mostly because while the geological record provides constraints on the origin and ages of the subducted ocean floor, it provides limited information about onset and cessation of the subduction and almost no constraints on the dimension of these oceans and the subduction zones that consumed them.</p><p>In this study, we follow a novel approach in estimating the dimension and evolution of these back-arc basin by using seismic tomography. Seismic tomography has revealed that we can image and trace subducted lithosphere relics. Imaged mantle structure is now being used to link sinking slabs with sutures and to define shape of a slab. Systematic comparison of regions where the timing of subduction is reasonably well constrained by geological data showed that slabs sink gradually through the mantle at rates more or less the same. This perspective enabled us to study slab shape as a function of absolute trench motion. While mantle stationary trenches tend to create steep slabs or slab walls, the flat-lying segments are formed where the overlying trenches are mobile relative to the mantle, normal facing during roll-back, overturned during slab advance.  Under the assumption of vertical sinking after break-off, it is also possible to locate the palaeo-trenches.  When combined with absolute plate motion reconstructions, tomographically determined volume and size of the subducted lithosphere can also be used to estimate the size/width of the prehistoric oceans. To this end, we build on and further develop concepts that relate absolute trench motion during subduction to modern slab geometry to evaluate the possible range of dimensions associated with opening and closure of the Iranian back-arc basins.</p>

The Brain Stem Saccadic Burst Generator Encodes Gaze in Three-Dimensional Space

2008 ◽  
Vol 99 (5) ◽  
pp. 2602-2616 ◽  
Author(s):  
Marion R. Van Horn ◽  
Pierre A. Sylvestre ◽  
Kathleen E. Cullen
Keyword(s):  
Eye Movements ◽  
Brain Stem ◽  
Dimensional Space ◽  
Three Dimensional ◽  
Saccadic Eye Movements ◽  
Three Dimensions ◽  
Related Information ◽  
Computer Based ◽  
Different Depths ◽  
The Brain

When we look between objects located at different depths the horizontal movement of each eye is different from that of the other, yet temporally synchronized. Traditionally, a vergence-specific neuronal subsystem, independent from other oculomotor subsystems, has been thought to generate all eye movements in depth. However, recent studies have challenged this view by unmasking interactions between vergence and saccadic eye movements during disconjugate saccades. Here, we combined experimental and modeling approaches to address whether the premotor command to generate disconjugate saccades originates exclusively in “vergence centers.” We found that the brain stem burst generator, which is commonly assumed to drive only the conjugate component of eye movements, carries substantial vergence-related information during disconjugate saccades. Notably, facilitated vergence velocities during disconjugate saccades were synchronized with the burst onset of excitatory and inhibitory brain stem saccadic burst neurons (SBNs). Furthermore, the time-varying discharge properties of the majority of SBNs (>70%) preferentially encoded the dynamics of an individual eye during disconjugate saccades. When these experimental results were implemented into a computer-based simulation, to further evaluate the contribution of the saccadic burst generator in generating disconjugate saccades, we found that it carries all the vergence drive that is necessary to shape the activity of the abducens motoneurons to which it projects. Taken together, our results provide evidence that the premotor commands from the brain stem saccadic circuitry, to the target motoneurons, are sufficient to ensure the accurate control shifts of gaze in three dimensions.

scholarly journals Three-dimensional dipole tracing of auditory brain-stem response (wave V).

1990 ◽  
Vol 33 (6) ◽  
pp. 749-753
Author(s):  
Yasutomo Yoshida ◽  
Ginichirou Ichikawa ◽  
Norio Uehara ◽  
Atushi Sakurai ◽  
Masafumi Nakagawa
Keyword(s):  
Brain Stem ◽  
Three Dimensional ◽  
Auditory Brain Stem Response ◽  
Auditory Brain Stem ◽  
Brain Stem Response ◽  
Dipole Tracing

STATIC AND DYNAMIC PERFORMANCE EVALUATION OF A PRE-STRESSED CONCRETE BRIDGE THROUGH FIELD TESTING AND MONITORING

2009 ◽  
Vol 09 (04) ◽  
pp. 711-728 ◽  
Author(s):  
C. S. CAI ◽  
M. ARAUJO ◽  
A. NAIR ◽  
X. SHI
Keyword(s):  
Quantitative Methods ◽  
Dynamic Performance ◽  
Three Dimensional ◽  
Field Tests ◽  
Field Measurements ◽  
Field Testing ◽  
Concrete Bridge ◽  
Bridge Structures ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element

This paper presents field tests performed on a slab-on-girder pre-stressed concrete bridge. The bridge was tested under static loading, crawling loading, and dynamic loading. A full three-dimensional finite element prediction under both static and dynamic loadings was carried out and the results were compared with the field measurements. While acoustic emission (AE) monitoring of bridge structures is not a new vista, the method has not been fully exploited in bridge monitoring. Though numerous quantitative methods have been proposed, they have not yet developed to be useful for actual field tests of bridges. Therefore, in this study, an attempt was made to use the intensity analysis technique for damage quantification using the AE method.

scholarly journals Chemical Decorations of “MARs” Residents in Orchestrating Eukaryotic Gene Regulation

2020 ◽  
Vol 8 ◽  
Author(s):  
Tanaya Roychowdhury ◽  
Samit Chattopadhyay
Keyword(s):  
Gene Regulation ◽  
Conformational Changes ◽  
Protein Interactions ◽  
Protein Function ◽  
Functional Outcomes ◽  
Three Dimensional ◽  
Limited Information ◽  
Post Translational Modification ◽  
Cellular Functions ◽  
3D Matrix

Genome organization plays a crucial role in gene regulation, orchestrating multiple cellular functions. A meshwork of proteins constituting a three-dimensional (3D) matrix helps in maintaining the genomic architecture. Sequences of DNA that are involved in tethering the chromatin to the matrix are called scaffold/matrix attachment regions (S/MARs), and the proteins that bind to these sequences and mediate tethering are termed S/MAR-binding proteins (S/MARBPs). The regulation of S/MARBPs is important for cellular functions and is altered under different conditions. Limited information is available presently to understand the structure–function relationship conclusively. Although all S/MARBPs bind to DNA, their context- and tissue-specific regulatory roles cannot be justified solely based on the available information on their structures. Conformational changes in a protein lead to changes in protein–protein interactions (PPIs) that essentially would regulate functional outcomes. A well-studied form of protein regulation is post-translational modification (PTM). It involves disulfide bond formation, cleavage of precursor proteins, and addition or removal of low-molecular-weight groups, leading to modifications like phosphorylation, methylation, SUMOylation, acetylation, PARylation, and ubiquitination. These chemical modifications lead to varied functional outcomes by mechanisms like modifying DNA–protein interactions and PPIs, altering protein function, stability, and crosstalk with other PTMs regulating subcellular localizations. S/MARBPs are reported to be regulated by PTMs, thereby contributing to gene regulation. In this review, we discuss the current understanding, scope, disease implications, and future perspectives of the diverse PTMs regulating functions of S/MARBPs.

A three-dimensional reconstruction of the human brain stem

1982 ◽  
Vol 57 (4) ◽  
pp. 491-495 ◽  
Author(s):  
Farhad Afshar ◽  
Eric Dykes
Keyword(s):  
Human Brain ◽  
Brain Stem ◽  
Computer Technology ◽  
Three Dimensional ◽  
Three Dimensional Reconstruction ◽  
Content Type ◽  
Stereotaxic Surgery ◽  
Stereotaxic Atlas ◽  
Dimensional Reconstruction ◽  
Fine Print

✓ Advances in computer technology and color graphics have been applied to the sections in a stereotaxic atlas of the human brain stem to enable three-dimensional reconstructions of nuclei and tracts. Techniques for viewing the reconstructed brain stem from multiple directions and in stereo have been achieved. The application of these methods and the use of color graphics are discussed with respect to stereotaxic surgery and computer dissection in neuroanatomical studies.

scholarly journals Lure, retain, and catch malaria mosquitoes. How heat and humidity improve odour-baited trap performance

2020 ◽  
Vol 19 (1) ◽  
Author(s):  
Antoine Cribellier ◽  
Jeroen Spitzen ◽  
Henry Fairbairn ◽  
Cedric van de Geer ◽  
Johan L. van Leeuwen ◽  
...  
Keyword(s):  
Short Range ◽  
Visual Cues ◽  
Three Dimensional ◽  
Field Testing ◽  
Counter Flow ◽  
Flight Behaviour ◽  
Baited Traps ◽  
Close Range ◽  
Malaria Mosquitoes ◽  
Host Cues

Abstract Background When seeking a human for a blood meal, mosquitoes use several cues to detect and find their hosts. From this knowledge, counter-flow odour-baited traps have been developed that use a combination of CO2, human-mimicking odour, visual cues and circulating airflow to attract and capture mosquitoes. Initially developed for monitoring, these traps are now also being considered as promising vector control tools. The traps are attractive to host-seeking mosquitoes, but their capture efficiency is low. It has been hypothesized that the lack of short-range host cues, such as heat and increased local humidity, often prevent mosquitoes from getting close enough to get caught; this lack might even trigger avoidance manoeuvres near the capture region. Methods This study investigated how close-range host cues affect the flight behaviour of Anopheles female malaria mosquitoes around odour-baited traps, and how this affects trap capture performance. For this, a novel counter-flow odour-baited trap was developed, the M-Tego. In addition to the usual CO2 and odour-blend, this trap can provide the short-range host cues, heat and humidity. Systematically adding or removing these two cues tested how this affected the trap capture percentages and flight behaviour. First, capture percentages of the M-Tego with and without short-range host cues to the BG-Suna trap were compared, in both laboratory and semi-field testing. Then, machine-vision techniques were used to track the three-dimensional flight movements of mosquitoes around the M-Tego. Results With heat and humidity present, the M-Tego captured significantly more mosquitoes as capture percentages almost doubled. Comparing the flight behaviour around the M-Tego with variable close-range host cues showed that when these cues were present, flying mosquitoes were more attracted to the trap and spent more time there. In addition, the M-Tego was found to have a better capture mechanism than the BG-Suna, most likely because it does not elicit previously observed upward avoiding manoeuvres. Conclusions Results suggest that adding heat and humidity to an odour-baited trap lures more mosquitoes close to the trap and retains them there longer, resulting in higher capture performance. These findings support the development of control tools for fighting mosquito-borne diseases such as malaria.

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