Muscular work as thermal behavior in humans

1980 ◽  
Vol 48 (6) ◽  
pp. 1020-1023 ◽  
Author(s):  
M. Caputa ◽  
M. Cabanac
Keyword(s):  
Extreme Values ◽  
Brain Temperature ◽  
Human Subjects ◽  
Muscular Activity ◽  
Bicycle Ergometer ◽  
Sweating Rate ◽  
Series Of Experiments ◽  
Skin Temperatures ◽  
The Brain ◽  
Head Covering

Human subjects were placed on a bicycle ergometer and left to pedal ad lib. for 43 min to warm themselves and thereby attain thermal comfort at an ambient temperature of 10 degrees C. Esophageal (Tes), tympanic (Tty), forehead, and hand skin temperatures were recorded. In addition, the work of pedaling was noted for each 2-min period. In some experiments sweating rate was also recorded. Two series of experiments were performed, the first with face fanning and the second with thermal insulation of the head. Face fanning resulted in decreased Tty, but in substantially increased Tes, which was 1.5 degrees C higher than Tty after an intense pedaling effort of 46-50 W. In experiments with head covering, a mild increase of both Tes and Tty was observed toward a position halfway between the extreme values obtained during face fanning. Simultaneously, pedaling intensity decreased to 16.7 W and the rate of sweating increased. In general, pedaling work was inversely proportional to intracranial temperature (Tty) and independent of trunk temperature (Tes). Therefore, motivation for muscular activity in humans exposed to cold appears to be goverened chiefly by the brain temperature.

scholarly journals Why the Readiness Potential Does Not Disprove Free Will

2021 ◽  
Vol 14 (1) ◽  
pp. 125-133
Author(s):  
Even Totland
Keyword(s):  
Free Will ◽  
Human Subject ◽  
Human Subjects ◽  
Readiness Potential ◽  
Neural Processes ◽  
Series Of Experiments ◽  
The Brain

Neuroscientist Benjamin Libet has conducted a series of experiments that reveal the existence of certain neural processes in the brain of human subjects, initiating an action prior to the human subject’s intention to act, thus seemingly threatening our idea of free will. The purpose of this paper is to show how these processes do not disprove any idea of free will one might have as one would, if accepting such a thesis, be committing two distinct mereological fallacies and ultimately, would treat the human subject as inhabiting some of its parts as opposed to being the sum of its parts.

scholarly journals Why the Readiness Potential Does Not Disprove Free Will

2021 ◽  
Vol 14 ◽  
pp. 124-132
Author(s):  
Even Totland ◽  
Keyword(s):  
Free Will ◽  
Human Subject ◽  
Human Subjects ◽  
Readiness Potential ◽  
Neural Processes ◽  
Series Of Experiments ◽  
The Brain

Neuroscientist Benjamin Libet has conducted a series of experiments that reveal the existence of certain neural processes in the brain of human subjects, initiating an action prior to the human subject’s intention to act, thus seemingly threatening our idea of free will. The purpose of this paper is to show how these processes do not disprove any idea of free will one might have as one would, if accepting such a thesis, be committing two distinct mereological fallacies and ultimately, would treat the human subject as inhabiting some of its parts as opposed to being the sum of its parts.

Effect of combined citicoline and glutamate antibodies on acute, generalized convusions induced by pentylenetetrazole in mice

2018 ◽  
pp. 24-29
Author(s):  
М.Н. Карпова ◽  
Л.В. Кузнецова ◽  
Н.Ю. Клишина ◽  
Л.А. Ветрилэ
Keyword(s):  
Drug Combination ◽  
Subcutaneous Injection ◽  
Seizure Activity ◽  
Experimental Conditions ◽  
Slow Progression ◽  
Experiment Control ◽  
Effective Doses ◽  
Experimental Justification ◽  
Series Of Experiments ◽  
The Brain

Цель исследования. На 2 моделях острых генерализованных судорог (ОГС), вызванных конвульсантом пентилентетразолом (ПТЗ), изучить эффективность сочетанного применения ноотропа цитиколина - препарата с противосудорожным действием, нейрорегенеративной, нейропротекторной активностью и антител (АТ) к глутамату, обладающих противосудорожной активностью. Методика. Эксперименты выполнены на мышах-самцах линии C57Bl/6 (n = 87) массой 22-28 г. Эффективность сочетанного применения цитиколина и АТ к глутамату изучали на двух моделях ОГС. Выполнено 2 серии экспериментов. В 1-й серии ОГС вызывали внутривенным введением 1% раствора ПТЗ со скоростью 0,01 мл/с. Для изучения эффективности сочетанного применения препаратов определяли минимальное противосудорожное действие цитиколина (Цераксон, «Nicomed Ferrer Internaсional, S.A.») и АТ к глутамату при их внутрибрюшинном введении. С этой целью цитиколин вводили в дозах 500 и 300 мг/кг за 1 ч до введения ПТЗ, АТ к глутамату - в дозах 5 и 2,5 мг/кг за 1 ч 30 мин до введения ПТЗ. АТ к глутамату получали путем гипериммунизации кроликов соответствующим конъюгированным антигеном. Во 2-й серии ОГС вызывали подкожным введением ПТЗ в дозе 85 мг/кг. Для изучения эффективности сочетанного действия изучаемых препаратов последние вводили в минимально действующих дозах, установленных в 1-й серии экспериментов. Контролем во всех сериях опытов служили животные, которым вводили в аналогичных условиях и в том же объеме физиологический раствор. Результаты. Показано, что сочетанное применение цитиколина и АТ к глутамату в минимально действующих дозах (300 и 2,5 мг/кг соответственно) при моделировании ОГС не вызывало повышения судорожной активности мозга и усиления противосудорожных свойств препаратов. Заключение. Cочетанное применение цитиколина и АТ к глутамату в минимально действующих дозах не вызывало повышения судорожной активности мозга, что свидетельствует о безопасности совместного применения препаратов. Проведенное исследование может служить также экспериментальным обоснованием возможности использования сочетанного применения данных препаратов при судорогах с целью замедления прогрессирования нейродегенеративных процессов и благоприятного влияния на когнитивные функции. Aim. To study the effectivity of a combination of citicoline, a nootropic substance with neuroregenerative, neuroprotective, and anticonvulsant actions, and glutamate antibodies (АB) with an anticonvulsant action in two models of acute generalized convulsions (AGC) caused by the convulsant pentylenetetrazole (PTZ). Methods. Experiments were conducted on C57Bl/6 mice (n = 87) weighing 22-28 g. Effects of combined citicoline and glutamate АB were studied on two models of AGС. In the first series of experiments, AGС was induced by intravenous infusion of a 1% PTZ solution at 0.01 ml/sec. In the second series, AGС was induced by a subcutaneous injection of PTZ 85 mg/kg. To evaluate efficacy of the drug combination minimum intraperitoneal anticonvulsant doses of citicoline (Tserakson, Nicomed Ferrer Internacional, S.A.) and glutamate АB were determined. To this purpose, citicoline was administered at 500 and 300 mg/kg 1 h prior to PTZ, and glutamate АB was administered at 5 and 2.5 mg/kg 90 min prior to PTZ. Glutamate АB was obtained by hyperimmunization of rabbits with a respective conjugated antigen. In the second series of experiments, AGС was induced by a subcutaneous injection of PTZ 85 mg/kg. To evaluate the effect of the drug combination, the drugs were administered at the minimum effective doses determined in the first series of experiment. Control animals were injected with the same volume of saline in the same experimental conditions. Results. The combination of citicoline and glutamate AB used at minimum effective doses of 300 and 2.5 mg/kg, respectively, did not increase the seizure activity in the brain and enhanced anticonvulsant properties of the drugs in two models of AGС. Conclusion. The combination of citicoline and glutamate AT at minimum effective doses did not increase the convulsive activity in the brain, which supported safety of the drug combination. Besides, this study can serve as an experimental justification for using the drug combination in convulsions to favorably influence cognitive functions and slow progression of neurodegenerative processes.

Cell and Molecular Biological Challenges of ICSI: ART before Science?

1998 ◽  
Vol 26 (1) ◽  
pp. 29-37 ◽  
Author(s):  
Gerald Schatten ◽  
Laura Hewitson ◽  
Calvin Simerly ◽  
Peter Sutovsky ◽  
Gabor Huszar
Keyword(s):  
Rhesus Monkeys ◽  
Nonhuman Primates ◽  
Assisted Reproductive Technologies ◽  
Clinical Investigation ◽  
Human Subjects ◽  
Reproductive Technologies ◽  
Published Data ◽  
New Methods ◽  
Institutional Review ◽  
Series Of Experiments

The general perception of how innovative assisted reproductive technologies (ART) are introduced is through a carefully controlled series of experiments in an animal model, such as the mouse. Only after the technique has been proven can one consider confirmatory studies on mammals closely related to humans, such as rhesus monkeys or other nonhuman primates. With this background of a peer-reviewed body of well-established published data, there is sufficient foundation and rationale to propose a clinical investigation to a responsible human subjects institutional review board (IRB). IRBs weigh the benefits and risks of the new methods to human subjects, and then consider the appropriate informed consent procedures for the particular case. Only after a large number of clinical studies are performed at multiple sites and are peer reviewed can the efficacy and safety of the innovative approach be clearly evaluated. At that time, the potential therapy can be responsibly offered to suitable beneficiaries.

scholarly journals Multifaceted origins of sex differences in the brain

2016 ◽  
Vol 371 (1688) ◽  
pp. 20150106 ◽  
Author(s):  
Margaret M. McCarthy
Keyword(s):  
Sex Differences ◽  
State Of The Art ◽  
Human Subjects ◽  
Special Issue ◽  
Molecular Analyses ◽  
The Past ◽  
Current State ◽  
Biological Variable ◽  
Males And Females ◽  
The Brain

Studies of sex differences in the brain range from reductionistic cell and molecular analyses in animal models to functional imaging in awake human subjects, with many other levels in between. Interpretations and conclusions about the importance of particular differences often vary with differing levels of analyses and can lead to discord and dissent. In the past two decades, the range of neurobiological, psychological and psychiatric endpoints found to differ between males and females has expanded beyond reproduction into every aspect of the healthy and diseased brain, and thereby demands our attention. A greater understanding of all aspects of neural functioning will only be achieved by incorporating sex as a biological variable. The goal of this review is to highlight the current state of the art of the discipline of sex differences research with an emphasis on the brain and to contextualize the articles appearing in the accompanying special issue.

Variables That Influence the Generation of Random Sequences: An Update

1997 ◽  
Vol 84 (2) ◽  
pp. 627-661 ◽  
Author(s):  
Peter Brugger
Keyword(s):  
Short Term Memory ◽  
Human Subjects ◽  
Complete Suppression ◽  
Random Generation ◽  
Short Term ◽  
Random Sequences ◽  
Potential Applications ◽  
Basic Experiments ◽  
The Brain ◽  
Relevant Work

This article updates Tune's 1964 review of variables influencing human subjects' attempts at generating random sequences of alternatives. It also covers aspects not included in the original review such as randomization behavior by patients with neurological and psychiatric disorders. Relevant work from animal research (spontaneous alternation paradigm) is considered as well. It is conjectured that Tune's explanation of sequential nonrandomness in terms of a limited capacity of short-term memory can no longer be maintained. Rather, interdependence among consecutive choices is considered a consequence of an organism's natural susceptibility to interference. Random generation is thus a complex action which demands complete suppression of any rule-governed behavior. It possibly relies on functions of the frontal lobes but cannot otherwise be “localized” to restricted regions of the brain. Possible developments in the field are briefly discussed, both with respect to basic experiments regarding the nature of behavioral nonrandomness and to potential applications of random-generation tasks.

scholarly journals Modeling Neuroimmune Interactions in Human Subjects and Animal Models to Predict Subtype-Specific Multidrug Treatments for Gulf War Illness

2021 ◽  
Vol 22 (16) ◽  
pp. 8546
Author(s):  
Francisco J. Carrera Arias ◽  
Kristina Aenlle ◽  
Maria Abreu ◽  
Mary A. Holschbach ◽  
Lindsay T. Michalovicz ◽  
...  
Keyword(s):  
Signaling Pathways ◽  
Human Subjects ◽  
Treatment Strategies ◽  
Gulf War ◽  
Clinical Samples ◽  
Stable States ◽  
Response Dynamics ◽  
Gulf War Illness ◽  
Bbb Permeability ◽  
The Brain

Gulf War Illness (GWI) is a persistent chronic neuroinflammatory illness exacerbated by external stressors and characterized by fatigue, musculoskeletal pain, cognitive, and neurological problems linked to underlying immunological dysfunction for which there is no known treatment. As the immune system and the brain communicate through several signaling pathways, including the hypothalamic–pituitary–adrenal (HPA) axis, it underlies many of the behavioral and physiological responses to stressors via blood-borne mediators, such as cytokines, chemokines, and hormones. Signaling by these molecules is mediated by the semipermeable blood–brain barrier (BBB) made up of a monocellular layer forming an integral part of the neuroimmune axis. BBB permeability can be altered and even diminished by both external factors (e.g., chemical agents) and internal conditions (e.g., acute or chronic stress, or cross-signaling from the hypothalamic–pituitary–gonadal (HPG) axis). Such a complex network of regulatory interactions that possess feed-forward and feedback connections can have multiple response dynamics that may include several stable homeostatic states beyond normal health. Here we compare immune and hormone measures in the blood of human clinical samples and mouse models of Gulf War Illness (GWI) subtyped by exposure to traumatic stress for subtyping this complex illness. We do this via constructing a detailed logic model of HPA–HPG–Immune regulatory behavior that also considers signaling pathways across the BBB to neuronal–glial interactions within the brain. We apply conditional interactions to model the effects of changes in BBB permeability. Several stable states are identified in the system beyond typical health. Following alignment of the human and mouse blood profiles in the context of the model, mouse brain sample measures were used to infer the neuroinflammatory state in human GWI and perform treatment simulations using a genetic algorithm to optimize the Monte Carlo simulations of the putative treatment strategies aimed at returning the ill system back to health. We identify several ideal multi-intervention strategies and potential drug candidates that may be used to treat chronic neuroinflammation in GWI.

scholarly journals Learning to synchronize: Midfrontal theta dynamics during rule switching

2020 ◽  
Author(s):  
Pieter Verbeke ◽  
Kate Ergo ◽  
Esther De Loof ◽  
Tom Verguts
Keyword(s):  
Negative Feedback ◽  
Human Subjects ◽  
Learning Task ◽  
Theta Oscillations ◽  
Prediction Errors ◽  
Hierarchical Learning ◽  
Theta Power ◽  
Negative Prediction ◽  
Theta Phase ◽  
The Brain

AbstractIn recent years, several hierarchical extensions of well-known learning algorithms have been proposed. For example, when stimulus-action mappings vary across time or context, the brain may learn two or more stimulus-action mappings in separate modules, and additionally (at a hierarchically higher level) learn to appropriately switch between those modules. However, how the brain mechanistically coordinates neural communication to implement such hierarchical learning, remains unknown. Therefore, the current study tests a recent computational model that proposed how midfrontal theta oscillations implement such hierarchical learning via the principle of binding by synchrony (Sync model). More specifically, the Sync model employs bursts at theta frequency to flexibly bind appropriate task modules by synchrony. 64-channel EEG signal was recorded while 27 human subjects (Female: 21, Male: 6) performed a probabilistic reversal learning task. In line with the Sync model, post-feedback theta power showed a linear relationship with negative prediction errors, but not with positive prediction errors. This relationship was especially pronounced for subjects with better behavioral fit (measured via AIC) of the Sync model. Also consistent with Sync model simulations, theta phase-coupling between midfrontal electrodes and temporo-parietal electrodes was stronger after negative feedback. Our data suggest that the brain uses theta power and synchronization for flexibly switching between task rule modules, as is useful for example when multiple stimulus-action mappings must be retained and used.Significance StatementEveryday life requires flexibility in switching between several rules. A key question in understanding this ability is how the brain mechanistically coordinates such switches. The current study tests a recent computational framework (Sync model) that proposed how midfrontal theta oscillations coordinate activity in hierarchically lower task-related areas. In line with predictions of this Sync model, midfrontal theta power was stronger when rule switches were most likely (strong negative prediction error), especially in subjects who obtained a better model fit. Additionally, also theta phase connectivity between midfrontal and task-related areas was increased after negative feedback. Thus, the data provided support for the hypothesis that the brain uses theta power and synchronization for flexibly switching between rules.

scholarly journals BrainNet: A Multi-Person Brain-to-Brain Interface for Direct Collaboration Between Brains

2018 ◽  
Author(s):  
Linxing Jiang ◽  
Andrea Stocco ◽  
Darby M. Losey ◽  
Justin A. Abernethy ◽  
Chantel S. Prat ◽  
...  
Keyword(s):  
Problem Solving ◽  
Magnetic Stimulation ◽  
Human Subjects ◽  
Occipital Cortex ◽  
Collaborative Problem Solving ◽  
Incorrect Decision ◽  
Brain Signals ◽  
Noisy Signals ◽  
Brain Interface ◽  
The Brain

ABSTRACTWe present BrainNet which, to our knowledge, is the first multi-human non-invasive direct brain-to-brain interface for collaborative problem solving. The interface combines electroencephalography (EEG) to record brain signals and transcranial magnetic stimulation (TMS) to deliver information noninvasively to the brain. The interface allows three human subjects to collaborate and solve a task using direct brain-to-brain communication. Two of the three subjects are designated as “Senders” whose brain signals are decoded using real-time EEG data analysis. The decoding process extracts each Sender’s decision about whether to rotate a block in a Tetris-like game before it is dropped to fill a line. The Senders’ decisions are transmitted via the Internet to the brain of a third subject, the “Receiver,” who cannot see the game screen. The Senders’ decisions are delivered to the Receiver’s brain via magnetic stimulation of the occipital cortex. The Receiver integrates the information received from the two Senders and uses an EEG interface to make a decision about either turning the block or keeping it in the same orientation. A second round of the game provides an additional chance for the Senders to evaluate the Receiver’s decision and send feedback to the Receiver’s brain, and for the Receiver to rectify a possible incorrect decision made in the first round. We evaluated the performance of BrainNet in terms of (1) Group-level performance during the game, (2) True/False positive rates of subjects’ decisions, and (3) Mutual information between subjects. Five groups, each with three human subjects, successfully used BrainNet to perform the Tetris task, with an average accuracy of 81.25%. Furthermore, by varying the information reliability of the Senders by artificially injecting noise into one Sender’s signal, we investigated how the Receiver learns to integrate noisy signals in order to make a correct decision. We found that like conventional social networks, BrainNet allows Receivers to learn to trust the Sender who is more reliable, in this case, based solely on the information transmitted directly to their brains. Our results point the way to future brain-to-brain interfaces that enable cooperative problem solving by humans using a “social network” of connected brains.

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