scholarly journals From decision to action: Detailed modelling of frog tadpoles reveals neuronal mechanisms of decision-making and reproduces unpredictable swimming movements in response to sensory signals

2021 ◽  
Vol 17 (12) ◽  
pp. e1009654
Author(s):  
Andrea Ferrario ◽  
Andrey Palyanov ◽  
Stella Koutsikou ◽  
Wenchang Li ◽  
Steve Soffe ◽  
...  
Keyword(s):  
Motor Nerve ◽  
Biomechanical Model ◽  
Whole Body ◽  
Sensory Stimuli ◽  
Sensory Signals ◽  
Neuronal Mechanisms ◽  
Cell Recording ◽  
Muscle Innervation ◽  
Sensory Pathway ◽  
The Brain

How does the brain process sensory stimuli, and decide whether to initiate locomotor behaviour? To investigate this question we develop two whole body computer models of a tadpole. The “Central Nervous System” (CNS) model uses evidence from whole-cell recording to define 2000 neurons in 12 classes to study how sensory signals from the skin initiate and stop swimming. In response to skin stimulation, it generates realistic sensory pathway spiking and shows how hindbrain sensory memory populations on each side can compete to initiate reticulospinal neuron firing and start swimming. The 3-D “Virtual Tadpole” (VT) biomechanical model with realistic muscle innervation, body flexion, body-water interaction, and movement is then used to evaluate if motor nerve outputs from the CNS model can produce swimming-like movements in a volume of “water”. We find that the whole tadpole VT model generates reliable and realistic swimming. Combining these two models opens new perspectives for experiments.

scholarly journals Whole animal modelling reveals neuronal mechanisms of decision-making and reproduces unpredictable swimming in frog tadpoles

2021 ◽  
Author(s):  
Andrea Ferrario ◽  
Andrey Palyanov ◽  
Stella Koutsikou ◽  
wen-chang li ◽  
Steve Soffe ◽  
...  
Keyword(s):  
Decision Making ◽  
Sensory Information ◽  
Whole Body ◽  
Sensory Stimuli ◽  
3 Dimensional ◽  
Complete Chain ◽  
Neuronal Mechanisms ◽  
Sensory Information Processing ◽  
Muscle Innervation ◽  
New Perspective

Animal behaviour is based on interaction between nervous, musculoskeletal and environmental systems. How does an animal process sensory stimuli, use it to decide whether and how to respond, and initiate the locomotor behaviour? We build the whole body computer models of a simple vertebrate with a complete chain of neural circuits and body units for sensory information processing, decision-making, generation of spiking activities, muscle innervation, body flexion, body-water interaction, and movement. Our Central Nervous System (CNS) model generates biologically-realistic spiking and reveals that sensory memory populations on two hindbrain sides compete for swimming initiation and first body flexion. Biomechanical 3-dimensional "Virtual Tadpole" (VT) model is constructed to evaluate if motor outputs of CNS model can produce swimming-like movements in a volume of "water". We find that whole animal modelling generates reliable and realistic swimming. The combination of CNS and VT models opens a new perspective for experiments with immobilised tadpoles.

Accelerated aging and aging process in the brain

2018 ◽  
Vol 29 (3) ◽  
pp. 233-240 ◽  
Author(s):  
Nickolay K. Isaev ◽  
Elisaveta E. Genrikhs ◽  
Maria V. Oborina ◽  
Elena V. Stelmashook
Keyword(s):  
Down Syndrome ◽  
Brain Aging ◽  
Werner Syndrome ◽  
Accelerated Aging ◽  
Whole Body ◽  
Chronic Oxidative Stress ◽  
Neuronal Mechanisms ◽  
Progeria Syndrome ◽  
Hutchinson Gilford Progeria Syndrome ◽  
The Brain

AbstractOne of the approaches to the research of the problem of aging is the study of genetic pathologies leading to accelerated aging, such as the Hutchinson-Gilford progeria syndrome, Werner syndrome, and Down syndrome. Probably, this approach can be used in an attempt to understand the neuronal mechanisms underlying normal and pathological brain aging. The analysis of the current state of scientific knowledge about these pathologies shows that in the Hutchinson-Gilford progeria and Werner syndrome, the rate of brain aging is significantly lower than the rate of whole body aging, whereas in Down syndrome, the brain ages faster than other organs due to amyloid-beta accumulation and chronic oxidative stress in the brain tissue. The main point of a previously proposed hypothesis is that the aging of higher animals and humans is associated with an increased level of reactive oxygen species in mitochondria with age, which activates apoptosis, thus reducing the number of functioning cells.

scholarly journals Neuronal Correlates of Many-To-One Sensorimotor Mapping in Lateral Intraparietal Cortex

2020 ◽  
Vol 30 (10) ◽  
pp. 5583-5596 ◽  
Author(s):  
Yang Zhou ◽  
Yining Liu ◽  
Mingsha Zhang
Keyword(s):  
Early Stage ◽  
Receptive Fields ◽  
Neuron Activity ◽  
Visual Neurons ◽  
Sensory Stimuli ◽  
Visual Cue ◽  
Lateral Intraparietal Cortex ◽  
Neuronal Mechanisms ◽  
The Brain ◽  
Single Neuron Activity

Abstract Efficiently mapping sensory stimuli onto motor programs is crucial for rapidly choosing appropriate behavioral responses. While neuronal mechanisms underlying simple, one-to-one sensorimotor mapping have been extensively studied, how the brain achieves complex, many-to-one sensorimotor mapping remains unclear. Here, we recorded single neuron activity from the lateral intraparietal (LIP) cortex of monkeys trained to map multiple spatial positions of visual cue onto two opposite saccades. We found that LIP neurons’ activity was consistent with directly mapping multiple cue positions to the associated saccadic direction (SDir) regardless of whether the visual cue appeared in or outside neurons’ receptive fields. Unlike the explicit encoding of the visual categories, such cue–target mapping (CTM)–related activity covaried with the associated SDirs. Furthermore, the CTM was preferentially mediated by visual neurons identified by memory-guided saccade. These results indicate that LIP plays a crucial role in the early stage of many-to-one sensorimotor transformation.

scholarly journals The brain dynamics of architectural affordances during transition

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Zakaria Djebbara ◽  
Lars Brorson Fich ◽  
Klaus Gramann
Keyword(s):  
Occipital Cortex ◽  
The Body ◽  
Brain Dynamics ◽  
Alpha Band ◽  
Time Frequency ◽  
Posterior Cingulate ◽  
Sensory Signals ◽  
Event Related Desynchronization ◽  
The Brain ◽  
Attentional Mechanisms

AbstractAction is a medium of collecting sensory information about the environment, which in turn is shaped by architectural affordances. Affordances characterize the fit between the physical structure of the body and capacities for movement and interaction with the environment, thus relying on sensorimotor processes associated with exploring the surroundings. Central to sensorimotor brain dynamics, the attentional mechanisms directing the gating function of sensory signals share neuronal resources with motor-related processes necessary to inferring the external causes of sensory signals. Such a predictive coding approach suggests that sensorimotor dynamics are sensitive to architectural affordances that support or suppress specific kinds of actions for an individual. However, how architectural affordances relate to the attentional mechanisms underlying the gating function for sensory signals remains unknown. Here we demonstrate that event-related desynchronization of alpha-band oscillations in parieto-occipital and medio-temporal regions covary with the architectural affordances. Source-level time–frequency analysis of data recorded in a motor-priming Mobile Brain/Body Imaging experiment revealed strong event-related desynchronization of the alpha band to originate from the posterior cingulate complex, the parahippocampal region as well as the occipital cortex. Our results firstly contribute to the understanding of how the brain resolves architectural affordances relevant to behaviour. Second, our results indicate that the alpha-band originating from the occipital cortex and parahippocampal region covaries with the architectural affordances before participants interact with the environment, whereas during the interaction, the posterior cingulate cortex and motor areas dynamically reflect the affordable behaviour. We conclude that the sensorimotor dynamics reflect behaviour-relevant features in the designed environment.

Stability as a constraint in sagittal plane human force exertion modeling

1998 ◽  
Vol 1 (1) ◽  
pp. 23-39
Author(s):  
Carter J. Kerk ◽  
Don B. Chaffin ◽  
W. Monroe Keyserling
Keyword(s):  
Muscle Strength ◽  
Ankle Joint ◽  
Coefficient Of Friction ◽  
Sagittal Plane ◽  
Biomechanical Model ◽  
Whole Body ◽  
The Stability ◽  
Joint Center ◽  
Static Conditions ◽  
Stability Limits

The stability constraints of a two-dimensional static human force exertion capability model (2DHFEC) were evaluated with subjects of varying anthropometry and strength capabilities performing manual exertions. The biomechanical model comprehensively estimated human force exertion capability under sagittally symmetric static conditions using constraints from three classes: stability, joint muscle strength, and coefficient of friction. Experimental results showed the concept of stability must be considered with joint muscle strength capability and coefficient of friction in predicting hand force exertion capability. Information was gained concerning foot modeling parameters as they affect whole-body stability. Findings indicated that stability limits should be placed approximately 37 % the ankle joint center to the posterior-most point of the foot and 130 % the distance from the ankle joint center to the maximal medial protuberance (the ball of the foot). 2DHFEC provided improvements over existing models, especially where horizontal push/pull forces create balance concerns.

scholarly journals Has molecular imaging delivered to drug development?

2017 ◽  
Vol 375 (2107) ◽  
pp. 20170112 ◽  
Author(s):  
Philip S. Murphy ◽  
Neel Patel ◽  
Timothy J. McCarthy
Keyword(s):  
Molecular Imaging ◽  
Drug Development ◽  
Clinical Studies ◽  
Pharmaceutical Research ◽  
Whole Body ◽  
Drug Candidate ◽  
Clinical Drug Development ◽  
Target Binding ◽  
The Brain ◽  
Clinical Drug

Pharmaceutical research and development requires a systematic interrogation of a candidate molecule through clinical studies. To ensure resources are spent on only the most promising molecules, early clinical studies must understand fundamental attributes of the drug candidate, including exposure at the target site, target binding and pharmacological response in disease. Molecular imaging has the potential to quantitatively characterize these properties in small, efficient clinical studies. Specific benefits of molecular imaging in this setting (compared to blood and tissue sampling) include non-invasiveness and the ability to survey the whole body temporally. These methods have been adopted primarily for neuroscience drug development, catalysed by the inability to access the brain compartment by other means. If we believe molecular imaging is a technology platform able to underpin clinical drug development, why is it not adopted further to enable earlier decisions? This article considers current drug development needs, progress towards integration of molecular imaging into studies, current impediments and proposed models to broaden use and increase impact. This article is part of the themed issue ‘Challenges for chemistry in molecular imaging’.

Bone-brain crosstalk and potential associated diseases

2016 ◽  
Vol 28 (2) ◽  
Author(s):  
Audrey Rousseaud ◽  
Stephanie Moriceau ◽  
Mariana Ramos-Brossier ◽  
Franck Oury
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Brain Development ◽  
Cognitive Functions ◽  
Intimate Relationship ◽  
Whole Body ◽  
Reciprocal Relationships ◽  
Skeletal Homeostasis ◽  
The Central Nervous System ◽  
The Brain

AbstractReciprocal relationships between organs are essential to maintain whole body homeostasis. An exciting interplay between two apparently unrelated organs, the bone and the brain, has emerged recently. Indeed, it is now well established that the brain is a powerful regulator of skeletal homeostasis via a complex network of numerous players and pathways. In turn, bone via a bone-derived molecule, osteocalcin, appears as an important factor influencing the central nervous system by regulating brain development and several cognitive functions. In this paper we will discuss this complex and intimate relationship, as well as several pathologic conditions that may reinforce their potential interdependence.

scholarly journals Tracheal occlusion-evoked respiratory load compensation and inhibitory neurotransmitter expression in rats

2014 ◽  
Vol 116 (8) ◽  
pp. 1006-1016 ◽  
Author(s):  
Hsiu-Wen Tsai ◽  
Paul W. Davenport
Keyword(s):  
Neural Network ◽  
Brain Stem ◽  
Breathing Pattern ◽  
Respiratory Rhythm ◽  
Inhibitory Neurotransmitter ◽  
Load Compensation ◽  
Efferent Projections ◽  
Motor Reflex ◽  
Sensory Pathway ◽  
The Brain

Respiratory load compensation is a sensory-motor reflex generated in the brain stem respiratory neural network. The nucleus of the solitary tract (NTS) is thought to be the primary structure to process the respiratory load-related afferent activity and contribute to the modification of the breathing pattern by sending efferent projections to other structures in the brain stem respiratory neural network. The sensory pathway and motor responses of respiratory load compensation have been studied extensively; however, the mechanism of neurogenesis of load compensation is still unknown. A variety of studies has shown that inhibitory interconnections among the brain stem respiratory groups play critical roles for the genesis of respiratory rhythm and pattern. The purpose of this study was to examine whether inhibitory glycinergic neurons in the NTS were activated by external and transient tracheal occlusions (ETTO) in anesthetized animals. The results showed that ETTO produced load compensation responses with increased inspiratory, expiratory, and total breath time, as well as elevated activation of inhibitory glycinergic neurons in the caudal NTS (cNTS) and intermediate NTS (iNTS). Vagotomized animals receiving transient respiratory loads did not exhibit these load compensation responses. In addition, vagotomy significantly reduced the activation of inhibitory glycinergic neurons in the cNTS and iNTS. The results suggest that these activated inhibitory glycinergic neurons in the NTS might be essential for the neurogenesis of load compensation responses in anesthetized animals.

Low positive yield from routine inclusion of the brain in whole-body 18F-FDG PET/CT imaging for noncerebral malignancies

2013 ◽  
Vol 34 (6) ◽  
pp. 540-543 ◽  
Author(s):  
Kuruva Manohar ◽  
Anish Bhattacharya ◽  
Bhagwant R. Mittal
Keyword(s):  
Fdg Pet ◽  
Ct Imaging ◽  
Whole Body ◽  
Pet Ct ◽  
18F Fdg ◽  
Fdg Pet Ct ◽  
The Brain

Whole-body adaptation to novel dynamics does not transfer between effectors

2021 ◽  
Author(s):  
Alison Pienciak-Siewert ◽  
Alaa A Ahmed
Keyword(s):  
Postural Control ◽  
Arm Movement ◽  
Movement Planning ◽  
Reaching Movements ◽  
Whole Body ◽  
Postural Control System ◽  
Movement Dynamics ◽  
Gradual Introduction ◽  
Postural Movement ◽  
The Brain

How does the brain coordinate concurrent adaptation of arm movements and standing posture? From previous studies, the postural control system can use information about previously adapted arm movement dynamics to plan appropriate postural control; however, it is unclear whether postural control can be adapted and controlled independently of arm control. The present study addresses that question. Subjects practiced planar reaching movements while standing and grasping the handle of a robotic arm, which generated a force field to create novel perturbations. Subjects were divided into two groups, for which perturbations were introduced in either an abrupt or gradual manner. All subjects adapted to the perturbations while reaching with their dominant (right) arm, then switched to reaching with their non-dominant (left) arm. Previous studies of seated reaching movements showed that abrupt perturbation introduction led to transfer of learning between arms, but gradual introduction did not. Interestingly, in this study neither group showed evidence of transferring adapted control of arm or posture between arms. These results suggest primarily that adapted postural control cannot be transferred independently of arm control in this task paradigm. In other words, whole-body postural movement planning related to a concurrent arm task is dependent on information about arm dynamics. Finally, we found that subjects were able to adapt to the gradual perturbation while experiencing very small errors, suggesting that both error size and consistency play a role in driving motor adaptation.

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