Most conceptual models of the organization of the cardiovascular system begin with the premise that the nervous system regulates the metabolic and nonmetabolic reflex adjustments of the circulation. These models assume that all the neurally mediated responses of the circulation are reactive, i.e., reflexes elicited by adequate stimuli. This target article suggests that the responses of the circulation are conditional in three senses. First, as Sherrington argued, reflexes are conditional in that they never operate in a vacuum (...) but in a context together with other reflexes. Guided by functional utility, they interact rather than add. Second, as Pavlov argued, stimuli acquire meanings as a result of experience. This notion of stimulus effect plus the Sherringtonian notion of conditionality suggest that association is one of the ways stimuli eliciting cardiovascular reflexes acquire their meanings and thus their relative strengths. Finally, as Skinner and others have argued, operants are responses that act upon the environment to obtain consequences – that is, stimuli. As operants, cardiovascular responses fulfill a major biological need, functioning proactively. The cardiovascular response is an integral component of the animal's behavior regardless of whether it is an elicited reflex or the eliciting stimulus acquired its properties as a result of the genetic inheritance of the animal or through experience, or the cardiovascular response is emitted in anticipation of an environmental consequence. The main theses of this essay are: (1) behavior is an integrated set of responses and the circulation is one of the response systems comprising behavior; (2) behavior is, in part, determined by its functional significance within a context; (3) the contextual factors operative at the time of the behavior have a major role in determining which of the set of possible responses will determine the final act, that is, which behavior will be the effective response and which other behaviors will be concomitants. (shrink)

Although a great deal of research addresses the neural basis of deliberate and intentional emotion-regulation strategies, less attention has been paid to the neural mechanisms involved in implicit forms of emotion regulation. Behavioural research suggests that romantically involved participants implicitly derogate the attractiveness of alternative partners, and the present study sought to examine the neural basis of this effect. Romantically committed participants in the present study were scanned with functional magnetic resonance imaging (fMRI) while indicating (...) whether they would consider each of a series of attractive (or unattractive) opposite-sex others as a hypothetical dating partner both while under cognitive load and no cognitive load. Successful derogation of attractive others during the no cognitive load compared to the cognitive load trials corresponded with increased activation in the ventrolateral prefrontal cortex (VLPFC) and posterior dorsomedial prefrontal cortex (pDMPFC), and decreased activation in the ventral striatum, a pattern similar to those reported in deliberate emotion-regulation studies. Activation in the VLPFC and pDMPFC was not significant in the cognitive load condition, indicating that while the derogation effect may be implicit, it nonetheless requires cognitive resources. Additionally, activation in the right VLPFC correlated with participants' level of relationship investment. These findings suggest that the RVLPFC may play a particularly important role in implicitly regulating the emotions that threaten the stability of a romantic relationship. (shrink)

Birds are not commonly admired for emotional expression, and when they are, the focus is typically on negative states; yet vocal behavior is considered a direct reflection of an individual’s emotional state. Given that over 4000 species of songbird produce learned, complex, context-specific vocalizations, we make the case that songbirds are conspicuously broadcasting distinct positive emotional states and that hearing songs can also induce positive states in other birds. Studies are reviewed that demonstrate that that the production of sexually motivated (...) song reflects an emotional state of anticipatory reward-seeking (i.e., mate-seeking), while outside the mating context song in gregarious flocks reflects a state of intrinsic reward. Studies are also reviewed that demonstrate that hearing song induces states of positive anticipation and reward. This review brings together numerous studies that highlight a potentially important role for the songbird nucleus accumbens, a region nearly synonymous with reward in mammals, in positive emotional states that underlie singing behavior and responses to song. It is proposed that the nucleus accumbens is part of an evolutionarily conserved circuitry that contributes context-dependently to positive emotional states that motivate and reward singing behavior and responses to song. Neural mechanisms that underlie basic emotions appear to be conserved and similar across vertebrates. Thus, these findings in songbirds have the potential to provide insights into interventions that can restore positive social interactions disrupted by mental health disorders in humans. (shrink)

Recent brain imaging studies using functional magnetic resonance imaging (fMRI) have implicated insula and anterior cingulate cortices in the empathic response to another’s pain. However, virtually nothing is known about the impact of the voluntary generation of compassion on this network. To investigate these questions we assessed brain activity using fMRI while novice and expert meditation practitioners generated a loving-kindness-compassion meditation state. To probe affective reactivity, we presented emotional and neutral sounds during the meditation and comparison periods. Our main hypothesis (...) was that the concern for others cultivated during this form of meditation enhances affective processing, in particular in response to sounds of distress, and that this response to emotional sounds is modulated by the degree of meditation training. The presentation of the emotional sounds was associated with increased pupil diameter and activation of limbic regions (insula and cingulate cortices) during meditation (versus rest). During meditation, activation in insula was greater during presentation of negative sounds than positive or neutral sounds in expert than it was in novice meditators. The strength of activation in insula was also associated with self-reported intensity of the meditation for both groups. These results support the role of the limbic circuitry in emotion sharing. The comparison between meditation vs. rest states between experts and novices also showed increased activation in amygdala, right temporo-parietal junction (TPJ), and right posterior superior temporal sulcus (pSTS) in response to all sounds, suggesting, greater detection of the emotional sounds, and enhanced mentation in response to emotional human vocalizations for experts than novices during meditation. Together these data indicate that the mental expertise to cultivate positive emotion alters the activation of circuitries previously linked to empathy and theory of mind in response to emotional stimuli.. (shrink)

Emotion is normally regulated in the human brain by a complex circuit consisting of the orbital frontal cortex, amygdala, anterior cingulate cortex, and several other interconnected regions. There are both genetic and environmental contributions to the structure and function of this circuitry. We posit that impulsive aggression and violence arise as a consequence of faulty emotion regulation. Indeed, the prefrontal cortex receives a major serotonergic projection, which is dysfunctional in individuals who show impulsive violence. Individuals vulnerable to faulty (...) class='Hi'>regulation of negative emotion are at risk for violence and aggression. Research on the neural circuitry of emotion regulation suggests new avenues of intervention for such at-risk populations. (shrink)

PLoS ONE 3(3): e1897. doi:10.1371/journal.pone.

D‐amino acids are being recognized as functionally important molecules in mammals. We recently identified endogenous D‐cysteine in mammalian brain. D‐cysteine is present in neonatal brain in substantial amounts (mM) and decreases with postnatal development. D‐cysteine binds to MARCKS and a host of proteins implicated in cell division and neurodevelopmental disorders. D‐cysteine decreases phosphorylation of MARCKS in neural progenitor cells (NPCs) affecting its translocation. D‐cysteine controls NPC proliferation by inhibiting AKT signaling. Exogenous D‐cysteine inhibits AKT phosphorylation at Thr 308 and (...) Ser 473 in NPCs. D‐cysteine treatment of NPCs led to 50% reduction in phosphorylation of Foxo1 at Ser 256 and Foxo3a at Ser 253. We hypothesize that in the developing brain endogenous D‐cysteine is as a physiologic regulator of NPC proliferation by inhibiting AKT signaling mediated by Foxo1 and Foxo3a. Endogenous D‐cysteine may regulate mammalian neurodevelopment with roles in schizophrenia and Alzheimer's disease (AD). (shrink)

Are there brain differences between believers and nonbelievers? In order to investigate the effect of religious beliefs on cognitive control, Michael Inzlicht and his collaborators measured the neural correlates of performance monitoring and affective responses to errors, specifically, the error-related negativity. ERN is a neurophysiological marker occurring within 100 ms of error commission, and generated in the anterior cingulate cortex. The researchers observed that religious conviction is marked by reduced reactivity in the ACC, a cortical system that is involved (...) in the experience of anxiety and is important for self-regulation. Thus, they claimed that these results offer a mechanism for the finding that religion is linked to positive mental health and low rates of mortality. (shrink)

Background: The regulation of muscle force is a vital aspect of sensorimotor control, requiring intricate neural processes. While neural activity associated with upper extremity force control has been documented, extrapolation to lower extremity force control is limited. Knowledge of how the brain regulates force control for knee extension and flexion may provide insights as to how pathology or intervention impacts central control of movement.Objectives: To develop and implement a neuroimaging-compatible force control paradigm for knee extension and flexion.Methods: (...) A magnetic resonance imaging safe load cell was used in a customized apparatus to quantify force during neuroimaging. Visual biofeedback and a target sinusoidal wave that fluctuated between 0 and 5 N was provided via an MRI-safe virtual reality display. Fifteen right leg dominant female participants completed a knee extension and flexion force matching paradigm during neuroimaging. The force-matching error was calculated based on the difference between the visual target and actual performance. Brain activation patterns were calculated and associated with force-matching error and the difference between quadriceps and hamstring force-matching tasks were evaluated with a mixed-effects model.Results: Knee extension and flexion force-matching tasks increased BOLD signal among cerebellar, sensorimotor, and visual-processing regions. Increased knee extension force-matching error was associated with greater right frontal cortex and left parietal cortex activity and reduced left lingual gyrus activity. Increased knee flexion force-matching error was associated with reduced left frontal and right parietal region activity. Knee flexion force control increased bilateral premotor, secondary somatosensory, and right anterior temporal activity relative to knee extension. The force-matching error was not statistically different between tasks.Conclusion: Lower extremity force control results in unique activation strategies depending on if engaging knee extension or flexion, with knee flexion requiring increased neural activity for the same level of force and no difference in relative error. These fMRI compatible force control paradigms allow precise behavioral quantification of motor performance concurrent with brain activity for lower extremity sensorimotor function and may serve as a method for future research to investigate how pathologies affect lower extremity neuromuscular function. (shrink)

Hormonal changes across the menstrual cycle have been shown to influence reward-related motivation and impulsive behaviors. Here, to compare neural mechanisms of cognitive impulse control during the mid-luteal phase (LP) versus during the late follicular phase (FP), we employed functional magnetic resonance imaging (fMRI) with an event-related monetary delay discounting (EMDD) behavioral task (study 1) and then employed resting state (RS)-fMRI (study 2). The imaging data were analyzed and related to behavior-associated neural activation. In study 1, women in (...) the late FP showed a preference for sooner rewards while exhibiting enhanced activity in the dorsal striatum (DS), whereas women in the mid-LP showed a preference for delayed, higher-value rewards with enhanced activity in the dorsolateral prefrontal cortex (dlPFC). Discount rate (transformed k) in the EMDD task correlated with functional connectivity (FC) of the DS-dlPFC circuitry, consistent with the possibility that DS-dlPFC circuitry may regulate impulsivity. In study 2, the right dlPFC was significantly more active in mid-LP than in late FP, and this effect was sensitive to estradiol (E2) and relative E2 levels during mid-LP. The magnitude of DS-dlPFC FC correlated negatively with psychometric impulsivity scores during the late FP. These results replicated findings from study 1 and further indicated that relative E2 levels may play an important role in increasing cognitive control during the mid-LP, which provides new insight into the treatment of conditions characterized by hyper-impulsivity, such as obsessive-compulsive disorder, Parkinson disease, and attention deficit hyperactivity disorder. In conclusion, our results suggest that cyclical gonadal hormones affect cognitive control on impulsive behavior periodically, possibility via DS-dlPFC circuitry. (shrink)

The negative co‐variation of life‐history traits such as fecundity and lifespan across species suggests the existence of ubiquitous trade‐offs. Mechanistically, trade‐offs result from the need to differentially allocate limited resources to traits like reproduction versus self‐maintenance, with selection favoring the evolution of optimal allocation mechanism. Here I discuss the physiological (endocrine) mechanisms that underlie optimal allocation rules and how such rules evolve. The hormone testosterone may mediate life‐history trade‐offs due to its pleiotropic actions in male vertebrates. Conservation in the actions (...) of testosterone in vertebrates has prompted the ‘evolutionary constraint hypothesis,’ which assumes that testosterone signaling mechanisms and male traits evolve as a unit. This hypothesis implies that the actions of testosterone are similar across sexes and species, and only the levels of circulating testosterone concentrations change during evolution. In contrast, the ‘evolutionary potential hypothesis’ proposes that testosterone signaling mechanisms and male traits evolve independently. In the latter scenario, the linkage between hormone and traits itself can be shaped by selection, leading to variation in trade‐off functions. I will review recent case studies supporting the evolutionary potential hypothesis and suggest micro‐evolutionary experiments to unravel the mechanistic basis of life‐history evolution. BioEssays 29: 133–144, 2007. © 2007 Wiley Periodicals, Inc. (shrink)

The neural basis of progress monitoring has received relatively little attention compared to other sub-processes that are involved in goal directed behavior such as motor control and response inhibition. Studies of error-monitoring have identified the dorsal anterior cingulate cortex (dACC) as a structure that is sensitive to conflict detection, and triggers corrective action. However, monitoring goal progress involves monitoring correct as well as erroneous events over a period of time. In the present research, 20 healthy participants underwent fMRI while (...) playing a game that involved monitoring progress towards either a numerical or a visuo-spatial target. The findings confirmed the role of the dACC in detecting situations in which the current state may conflict with the desired state, but also revealed activations in the frontal and parietal regions, pointing to the involvement of processes such as attention and working memory in monitoring progress over time. In addition, activation of the cuneus was associated with monitoring progress towards a specific target presented in the visual modality. This is the first time that activation in this region has been linked to higher-order processing of goal-relevant information, rather than low-level anticipation of visual stimuli. Taken together, these findings identify the neural substrates involved in monitoring progress over time, and how these extend beyond activations observed in conflict and error monitoring. (shrink)

Mood in humans is a complex phenomenon that integrates emotion , cognition, perception, ideation, and action in a coherent manner. In bipolar disorder extremes of mood occur outside the normal range, in which all the above functions are coherently affected. Mood is controlled by a series of separate but interactive brain circuits that involve much of the brain, but particularly the limbic system. The question addressed in this paper is whether the coordination of all these separate systems into one coherent (...) functional mood is mediated by non-linear dynamics acting between these systems as equal participants; or whether it is affected by a single master regulator controlling the others. The possible roles, as master regulators, of non-linear dynamically linked populations of neurons, and of the C1–C3 adrenergic nuclei in the medulla is discussed. (shrink)

A network of gene regulation organized in a hierarchical and combinatorial manner is crucially involved in the development of the neural network, and has to be considered one of the main substrates of genetic change in its evolution. Though qualitative features may emerge by way of the accumulation of rather unspecific quantitative changes, it is reasonable to assume that at least in some cases specific combinations of regulatory parts of the genome initiated new directions of evolution, leading to (...) novel capabilities of the brain. These notions are applied, in this paper, to the evolution of the capability of cognition-based human empa­thy. It is suggested that it has evolved as a secondary effect of the evolution of strategic thought. Development of strategies depends on abstract representations of one’s own pos­sible future states in one’s own brain to allow assessment of their emotional desirability, but also on the representation and emotional evaluation of possible states of others, allowing anticipation of their behaviour. This is best achieved if representations of others are con­nected to one’s own emotional centres in a manner similar to self-representations. For this reason, the evolution of the human brain is assumed to have established representations with such linkages. No group selection is involved, because the quality of strategic thought affects the fitness of the individual. A secondary effect of this linkage is that both the actual states and the future perspectives of others elicit vicarious emotions, which may contribute to the motivations of altruistic behaviour. (shrink)

This study provides evidence supporting the operation of a novel cognitive process of a somatic seat of attention, or ego-center, whose somatic location is under voluntary control and that provides access to differential emotional resources. Attention has typically been studied in terms of what it is directed toward, but it can also be associated with a localized representation in the body image that is experienced as the source or seat of attention—an aspect that has previously only been studied by subjective (...) techniques. Published studies of this phenomenon under terms such as egocenter or self-location suggest that the seat of attention can be situated in various ways within the experienced body, resulting in what are here referred to as different attentional stances. These studies also provide evidence that changes in attentional stance are associated with differences in cognitive skill, emotional temperament, self-construal, and social and moral attitudes, as well as with access to certain states of consciousness. In the present study, EEG results from multiple trials of each of 11 specific attentional stances confirmed that patterns of neural activity associated with the voluntarily control of attentional stances can be reliably measured, providing evidence for a differential neural substrate underlying the subjective location of the seat of attention. Additionally, brain activation patterns for the attentional stances showed strong correlations with EEG signatures associated with specific positive emotional states and with arousal, confirming that differential locations of the seat of attention can be objectively associated with different emotion states, as implied in previous literature. The ability to directly manage the seat of attention into various attentional stances holds substantial potential for facilitating access to specific cognitive and emotional resources in a new way. (shrink)

Several recent research findings have implicated brain-derived neurotrophic factor (BDNF) as a mediator of neuronal plasticity. The BDNF gene is under extensive epigenetic regulation, which modulates how much or how little environmental experiences become encoded within neurons and neural circuits. Future scientific progress within the postgenomic paradigm requires elucidation of the functional trajectory in neogenetic and environment interactions.

Osteoclasts, the multinucleated cells primarily responsible for dissolution of bone tissue, form by fusion of precursors that circulate in the bloodstream. A variety of factors have been shown to affect the mature osteoclast and its progenitor cell, such as calcium‐regulating hormones, products of the immune system, and constituents of the arachidonic acid cascade. To date, however, the osteoclast precursor has not been identified. Furthermore, there is limited information on the factors that influence osteoclast development and regulation, reflecting in part (...) the paucity of data on the osteoclast cell surface. Recent progress in understanding osteoclasts formation and function is discussed. (shrink)

Thirty years after its initial characterization and more than 1000 publications listed in PubMed describing its properties, the small (ca15 kDa) protein profilin continues to surprise us with new, recently discovered functions. Originally described as an actin‐binding protein, profilin has now been shown to interact with more than a dozen proteins in mammalian cells. Some of the more recently described and intriguing interactions are within neurons involving a neuronal profilin family member. Profilin is now regarded as a regulator of various (...) cellular processes such as cytoskeletal dynamics, membrane trafficking and nuclear transport. Profilin is a necessary element in key steps of neuronal differentiation and synaptic plasticity, and embodies properties postulated for a synaptic tag. These findings identify profilin as an important factor linking cellular and behavioural plasticity in neural circuits. BioEssays 30:994–1002, 2008. © 2008 Wiley Periodicals, Inc. (shrink)

Disruptions in chromatin regulator genes are frequently the cause of neurodevelopmental and neuropsychiatric disorders. Chromatin regulators are widely expressed in the brain, yet symptoms suggest that specific circuits can be preferentially altered when they are mutated. Using Drosophila allows targeted manipulation of chromatin regulators in defined neuronal classes, lineages, or circuits, revealing their roles in neuronal precursor self‐renewal, dendrite and axon targeting, neuron diversification, and the tuning of developmental signaling pathways. Phenotypes arising from chromatin regulator disruption are context dependent – (...) defined by interaction networks between the regulators, transcription factors, and chromatin remodeling complex partners. Future challenges are to determine the complexity of partner interactions, and to ascertain the degree to which cognitive deficits are due to loss of chromatin regulator activity in building a circuit or in maintaining homeostasis and activity within it. (shrink)

Intermediate filaments (IFs) formed by vimentin are less understood than their cytoskeletal partners, microtubules and F‐actin, but the unique physical properties of IFs, especially their resistance to large deformations, initially suggest a mechanical function. Indeed, vimentin IFs help regulate cell mechanics and contractility, and in crowded 3D environments they protect the nucleus during cell migration. Recently, a multitude of studies, often using genetic or proteomic screenings show that vimentin has many non‐mechanical functions within and outside of cells. These include signaling (...) roles in wound healing, lipogenesis, sterol processing, and various functions related to extracellular and cell surface vimentin. Extracellular vimentin is implicated in marking circulating tumor cells, promoting neural repair, and mediating the invasion of host cells by viruses, including SARS‐CoV, or bacteria such as Listeria and Streptococcus. These findings underscore the fundamental role of vimentin in not only cell mechanics but also a range of physiological functions. Also see the video abstract here https://youtu.be/YPfoddqvz-g. (shrink)

We propose a cognitive and neurobiological model by which curiosity regulates affective memory, by positively biasing memory encoding through the promotion of emotion regulation. We begin with a brief overview of curiosity's observed emotional effects. Then we introduce three prominent models of affective memory encoding to suggest that the dopaminergic modulation of encoding associated with curiosity may positively bias memory processes. We situate the role of curiosity role in emotion regulation relative to its promotion of abstract thinking and (...) cognitive flexibility. We then identify the neural processes associated with abstraction and flexibility observed in the left inferior frontal gyrus, the dorsal anterior cingulate cortex, and the lateral prefrontal cortex as the neurobiological mechanisms underlying our framework. (shrink)

The mental health of young people is a growing public health concern. With socio-emotional difficulties in youth often resulting in psychiatric disorders later in life and most with mental health conditions rather stabilizing in time, it is essential to support healthy socio-emotional development. With a comprehensive definition of mental health, since emotion regulation plays a critical role in prevention, it becomes imperative to better understand how children effectively manage their emotions from an early age. Determining effective use of ER (...) skills relies on adequate measurements. Typical methods of data collection in children present consistent shortcomings. This review addresses research findings considering the suitability of the late positive potential measured through electroencephalogram as a neural indicator of ER in children and youth. There is growing evidence, as reported in this review, that indicates that the late positive potential may be a reliable neural indicator of children's cognitive reappraisal abilities more specifically. Results generally suggest that the late positive potential amplitudes are sensitive to directed reappraisal in children. However, given the scant research, questions remain regarding developmental trends, methodology, interindividual variability, reappraisal of various stimuli, and how the late positive potential may relate to more traditional measures of ER. Directions for future research are provided, which are expected to address unanswered research questions and fill literature gaps. Taken together, the findings reviewed indicate that the late positive potential is generally sensitive to directed cognitive reappraisal in children and that there is promise of establishing this neural marker as an indicator of ER. (shrink)

Neurodevices that collect neural (or brain activity) data have been characterised as having the ability to register the inner workings of human mentality. There are concerns that the proliferation of such devices in the consumer-directed realm may result in the mass processing and commercialisation of neural data (as has been the case with social media data) and even threaten the mental privacy of individuals. To prevent this, some argue that all raw neural data should be conceptualised and (...) regulated as “medical data” even if it is collected from consumer-directed devices in obviously non-clinical settings. In this paper, we argue that without a clearer formulation of what does and does not count as medical data, this approach might also uncritically enlarge the scope for medical influence and an unwarranted medicalisation of everyday aspects of mental life. Indeed, if we were to accept the position that all neural data is medical data because it offers insights into personally sensitive information (such a person’s thoughts, emotions, or intentions) then this could even unnecessarily expand the boundaries of medical data to other forms of data that otherwise seem to be non-clinical. If all brain data (neural activity data) is considered to be medical data even when collected from consumer-directed devices then we might unintentionally reduce meaningful distinctions between what is and what is not rightfully in the purview of medicine. (shrink)

In addition to active wake, emotions are generated and experienced in a variety of functionally different states such as those of sleep, during which external stimulation and cognitive control are lacking. The neural basis of emotions can be specified by regarding the multitude of emotion-related brain states, as well as the distinct neuro- and psychodynamic stages (generation and regulation) of emotional experience.

The renin-angiotensin system (RAS) is critical in sodium and blood pressure (BP) regulation, and in cardiovascular-renal (CVR) diseases and therapeutics. As a contribution to SAPHIR project, we present a realistic computer model of renin production and circulating RAS, integrated into Guyton’s circulatory model ( GCM ). Juxtaglomerular apparatus, JGA , and Plasma modules were implemented in C ++/M2SL (Multi-formalism Multi-resolution Simulation Library) for fusion with GCM . Matlab © optimization toolboxes were used for parameter identification. In JGA , renin (...) production and granular cells recruitment (GCR) are controlled by perfusion pressure (PP), macula densa (MD), angiotensin II (Ang II), and renal sympathetic activity (RSNA). In Plasma , renin and ACE (angiotensin-converting enzyme) activities are integrated to yield Ang I and II. Model vs. data deviation is given as normalized root mean squared error (nRMSE; n points). Identification: JGA and Plasma parameters were identified against selected experimental data. After fusion with GCM : (1) GCR parameters were identified against Laragh’s PRA-natriuresis nomogram; (2) Renin production parameters were identified against two sets of data ([renin] transients vs. ACE or renin inhibition). Finally, GCR parameters were re-identified vs. Laragh’s nomogram (nRMSE 8%, n = 9). Validation: (1) model BP, PRA and [Ang II] are within reported ranges, and respond physiologically to sodium intake; (2) short-term Ang II infusion induces reported rise in BP and PRA. The modeled circulating RAS, in interaction with an integrated CVR, exhibits a realistic response to BP control maneuvers. This construction will allow for modelling hypertensive and CVR patients, including salt-sensitivity, polymorphisms, and pharmacotherapeutics. (shrink)

Physiological investigation has demonstrated that the central nervous system monitors body composition and adjusts energy intake and expenditure to stabilize total adipose tissue mass. Genetic variations in the signalling molecules involved in this regulatory system account for the heritable component of body fat content. The application of molecular techniques to rodent models of Mendelian obesity has resulted in the characterization of five loci at which mutations produce an abnormal accumulation of body fat. The genes at these loci include agouti, which (...) encodes a molecule that antagonizes the binding of alpha melanocyte‐stimulating hormone to its receptor; fat, which encodes carboxypeptidase E; tubby, which encodes a putative phosphodiesterase; obese, which encodes a circulating satiety protein; and diabetes, which encodes the receptor for the obese gene product. A more detailed understanding of the functional interrelationships of these genes should lead to important new insights into the causes and potential therapies for human obesity. (shrink)

Summary Sexual communication in most species of fireflies is a male±female dialogue of precisely timed flashes of bioluminescent light. The biochemical reactions underlying firefly bioluminescence have been known for 30 years and are now exploited in biomedical assays and other commercial applications. Several aspects of flash regulation are also understood: flash rhythm is controlled by a central pattern generator, and individual flashes are neurally triggered, with octopamine serving as the transmitter. The molecular oxygen needed by the biochemical reactants is (...) delivered by a network of tracheal arborizations extending throughout the light organ (lantern).However, the actual means by which oxygen quickly reaches the reactants packaged within specialized photocytes and the specific event(s) triggered by neural action have not been identified; termination of axons away from the photocytes has exacerbated the latter problem. A recent paper(1) by a consortium of cell and evolutionary biologists, however, reports that nitric oxide (NO), manufactured and released in response to neuronal discharge, is the missing link by which neural action in the firefly lantern yields a sudden flash of light. BioEssays 23:992±995, 2001. ß 2001 John Wiley & Sons, Inc. (shrink)

In this single-blind within-subject study, autonomic and EEG variables were compared during 10-min, order-balanced eyes-closed rest and Transcendental Meditation (TM) sessions. TM sessions were distinguished by (1) lower breath rates, (2) lower skin conductance levels, (3) higher respiratory sinus arrhythmia levels, and (4) higher alpha anterior-posterior and frontal EEG coherence. Alpha power was not significantly different between conditions. These results were seen in the first minute and were maintained throughout the 10-min sessions. TM practice appears to (1) lead to a (...) state fundamentally different than eyes-closed rest; (2) result in a cascade of events in the central and autonomic nervous systems, leading to a rapid change in state (within a minute) that was maintained throughout the TM session; and (3) be best distinguished from other conditions through autonomic and EEG alpha coherence patterns rather than alpha power. Two neural networks that may mediate these effects are suggested. The rapid shift in physiological functioning within the first minute might be mediated by a ''neural switch'' in prefrontal areas inhibiting activity in specific and nonspecific thalamocortical circuits. The resulting ''restfully alert'' state might be sustained by a basal ganglia-corticothalamic threshold regulation mechanism automatically maintaining lower levels of cortical excitability. (shrink)

To orchestrate behaviors for survival, multiple psychological components have evolved. The current theories do not clearly distinguish the distinct components. In this article, we provide a unified theoretical framework. To optimize survival, there should be four components; (1) “need”, an alarm based on a predicted deficiency. (2) “motivation”, a direct behavior driver. (3) “pleasure”, a teacher based on immediate outcomes. (4) “utility”, a teacher based on final delayed outcomes. For behavior stability, need should be accumulated into motivation to drive behavior. (...) Based on the immediate outcome of the behavior, the pleasure should teach whether to continue the current behavior. Based on the final delay outcome, the utility should teach whether to increase future behavior by reshaping the other three components. We provide several neural substrate candidates in the food context. The proposed theoretical framework, in combination with appropriate experiments, will unravel the neural components responsible for each theoretical component. (shrink)

There is some complementarity of models for the origin of the electroencephalogram (EEG) and neural network models for information storage in brainlike systems. From the EEG models of Freeman, of Nunez, and of the authors' group we argue that the wavelike processes revealed in the EEG exhibit linear and near-equilibrium dynamics at macroscopic scale, despite extremely nonlinear – probably chaotic – dynamics at microscopic scale. Simulations of cortical neuronal interactions at global and microscopic scales are then presented. The simulations (...) depend on anatomical and physiological estimates of synaptic densities, coupling symmetries, synaptic gain, dendritic time constants, and axonal delays. It is shown that the frequency content, wave velocities, frequency/wavenumber spectra and response to cortical activation of the electrocorticogram (ECoG) can be reproduced by a “lumped” simulation treating small cortical areas as single-function units. The corresponding cellular neural network simulation has properties that include those of attractor neural networks proposed by Amit and by Parisi. Within the simulations at both scales, sharp transitions occur between low and high cell firing rates. These transitions may form a basis for neural interactions across scale. To maintain overall cortical dynamics in the normal low firing-rate range, interactions between the cortex and the subcortical systems are required to prevent runaway global excitation. Thus, the interaction of cortex and subcortex via corticostriatal and related pathways may partly regulate global dynamics by a principle analogous to adiabatic control of artificial neural networks. (shrink)

In lieu of an abstract, here is a brief excerpt of the content:Rhetorical Circulation in Late CapitalismNeoliberalism and the Overdetermination of Affective EnergyCatherine ChaputIn the world we have known since the nineteenth century, a series of governmental rationalities overlap, lean on each other, challenge each other, and struggle with each other: art of government according to truth, art of government according to the rationality of the sovereign state, and art of government according to the rationality of economic agents, and (...) more generally, according to the rationality of the governed themselves. And it is all these different arts of government, all these different types of ways of calculating, rationalizing, and regulating the art of government which, overlapping with each other, broadly speaking constitute the object of political debate.Michel Foucault, The Birth of BiopoliticsCritical rhetoricians interested in the power dynamics between rhetoric and capitalism have established for themselves the ambitious task of explaining how multiple, intertwined rationalities govern individual and collective [End Page 1] behavior in relationship to the ever-shifting logics of capitalism. Approaches to this complicated directive frequently envision rhetoric as a mediating force among agentive subjects who act within well-defined political economic landscapes. Wedded to a political-communicative model wherein appropriate rhetorical choices persuade those with authority to distribute disputed political and economic rights, rhetorical theory becomes a sophisticated handbook for discovering topoi and executing decorous statements. This focus, according to Ronald Walter Greene, results in a "permanent anxiety over the meaning and potential of rhetorical agency" that positions rhetoricians as "moral entrepreneurs scolding, correcting, and encouraging the body politic" (2004, 188, 189). Committing themselves to endless debates about correct responses in situated spaces, rhetorical theories that underscore agency lose site of the world in flux and of our participation in that world's unpredictable unfoldings. Alternatively, Greene suggests rethinking rhetorical theory through a materialist-communicative model wherein the immaterial labor of communication produces value. Conceptualizing discursive practices as a form of labor rather than a form of political signification sidesteps anxiety about well-chosen language and emphasizes the life-affirming activity involved in deciphering issues, inventing paths through those issues, and communicating new ideas to others. In short, Greene's materialist model challenges critical rhetoricians to end their perennial search for a discursive key to the storehouse of political economic goods (a practice propelled by liberal democratic hopes) so that they can begin to invent analyses and modes of production better suited to the contours of contemporary neoliberalism.Unlike liberalism's clearly assigned spaces for public life and private life or work time and leisure time, neoliberal spaces bear few obvious markers. The neoliberal landscape consists of blurred boundaries that fold into one another: information flows almost instantaneously, commodities and people transgress national boundaries, time accelerates, space collapses, and distinctions between such classic demarcations as agent and subject or politics and economics erode. Facilitated by dramatic changes in our sociopolitical boundaries, economic neoliberalism, what James Arnt Aune calls "economic correctness" (2001), reigns throughout vast uneven terrains opened up from the imploded borders of our liberal world. While economics does indeed rule the neoliberal landscape, it does not do so according to uncompromising rationalism. Political and cultural practices flowing into the previously segregated spaces of economics enable market rule through logics that operate entirely outside the rational-irrational divide. Economic neoliberalism moves from situation to situation, disregarding spatial boundaries between the political, economic, [End Page 2] and cultural realms as well as their attendant modes of persuasion, wearing away at the rhetorical linkages between appropriate discursive choices and agentive power.Regardless of the particularities of neoliberalism's spaces, structures, and governing practices, many rhetoricians continue to mediate among different worldviews based on outmoded liberal gauges. Some rhetorical theorists, for instance, maintain that the problematics of neoliberalism result from an imbalance between reason and passion. Even though the most ardent supporters of neoliberal practices hold firmly to a belief in its scientific rationality, rhetorical theorists often argue that passion overpowers reason in neoliberal discourse. The rhetorical form that sustains this disequilibrium is, according to Bradford Vivian, neoliberal epideictic. Based on an impassioned identification, epideictic texts "unite an otherwise fractured citizenry in a dynamic affective experience" (Vivian 2006, 15). Epideictic rhetoric functions didactically to unite the public... (shrink)

Excessive alcohol use has adverse effects on the central nervous system (CNS) and can lead to alcohol use disorders (AUDs). Recent studies have suggested that myelin reductions may directly contribute to CNS dysfunctions associated with AUDs. Myelin consists of compact lipid membranes wrapped around axons to provide electrical insulation and trophic support. Regulation of myelin is considered as a new form of neural plasticity due to its profound impacts on the computation of neural networks. In this review, (...) the authors first discuss experimental evidence showing how alcohol exposure causes demyelination in different brain regions, often accompanied by deficits in cognition and emotion. Next, they discuss postulated molecular and cellular mechanisms underlying alcohol's impact on myelin. It is clear that more extensive investigations are needed in this important but underexplored research field in order to gain a better understanding of the myelin‐behavior relationship and to develop new treatment strategies for AUDs. (shrink)

Through the overall situation of athletes’ competition pressure, the pressure level of participating athletes can be understood and revealed. Analyzing the sources of stress and influencing factors of athletes can find measures to relieve and reduce stress and provide theoretical reference for the regulation of athletes’ competition pressure. Based on genetic algorithm and neural network theory, this paper proposes a method of tracing the sports competition pressure based on genetic algorithm backpropagation neural network to solve the problem (...) that traditional neural network learning algorithm is slow and easy to fall into local minimum. There is no significant difference between male and female athletes in the level of competition pressure. Athletes have the same training methods and the same goals, and the competition pressure tends to be the same, with no obvious difference; athletes with different educational backgrounds have no significant differences in training, academics, sports injuries, interpersonal relationships, social expectations, and evaluations. Due to the particularity of the stage, the competition pressure of fourth-year undergraduate and third-year masters is significantly higher than that of other grades. The number of athletes participating in college table tennis tournaments has very significant differences in competition dimensions. There is significant difference in training and self-expectation dimension difference. The competition pressure of athletes who participated in the college table tennis championship for the first time was significantly higher than that of athletes who participated repeatedly. There were significant differences between athletes before and after adapting to the venue. Before adapting to the venue, the competition pressure of athletes is generally greater. After adapting to the venue, the competition pressure of athletes has been relieved. (shrink)

Emotion regulation is an umbrella term to describe interactive, goal-dependent explicit and implicit processes that are intended to help an individual manage and shift an emotional experience. The primary window for appropriate emotion regulation development occurs during the infant, toddler, and preschool years. Atypical emotion regulation development is considered a risk factor for mental health problems and has been implicated as a primary mechanism underlying childhood pathologies. Current treatments are predominantly verbal- and behavioral-based and lack the opportunity (...) to practice in-the-moment management of emotionally charged situations. There is also an absence of caregiver-child interaction in these treatment strategies. Based on behavioral and neural support for music as a therapeutic mechanism, the incorporation of intentional music experiences, facilitated by a music therapist, may be one way to address these limitations. Musical Contour Regulation Facilitation is an interactive therapist-child music-based intervention for emotion regulation development practice in preschoolers. The Musical Contour Regulation Facilitation intervention uses the deliberate contour and temporal structure of a music therapy session to mirror the changing flow of the caregiver-child interaction through the alternation of high arousal and low arousal music experiences. The purpose of this paper is to describe the Therapeutic Function of Music, a theory-based description of the structural characteristics for a music-based stimulus to musically facilitate developmentally appropriate high arousal and low arousal in-the-moment emotion regulation experiences. The Therapeutic Function of Music analysis is based on a review of the music theory, music neuroscience, and music development literature and provides a preliminary model of the structural characteristics of the music as a core component of the Musical Contour Regulation Facilitation intervention. (shrink)

In the evaluation of teaching quality, aiming at the shortcomings of slow convergence of BP neural network and easy to fall into local optimum, an online teaching quality evaluation model based on analytic hierarchy process and particle swarm optimization BP neural network is proposed. Firstly, an online teaching quality evaluation system was established by using the analytic hierarchy process to determine the weight of each subsystem and each index in the online teaching quality evaluation system and then combined (...) with actual experience, the risk value of each index was constructed according to safety regulations. The regression model is established through BP neural network, and the weight and threshold of the model are optimized by the particle swarm algorithm. Based on the online teaching quality evaluation model of BP neural network, the parameters of the model are constantly adjusted, the appropriate function is selected, and the particle swarm algorithm which is used in the training and learning process of the neural network is optimized. The scientificity of the questionnaire was verified by reliability and validity test. According to the scoring results and combined with the weight coefficient of each indicator in the online course quality evaluation index system, the key factors affecting the quality of online courses were obtained. Based on the survey data, descriptive statistics, analysis of variance, and Pearson’s correlation coefficient method are used to verify the research hypothesis and obtain valuable empirical results. By comparing the model with the standard BP model, the results show that the accuracy of the PSO-BP model is higher than that of the standard BP model and PSO-BP effectively overcomes the shortcomings of the BP neural network. (shrink)

This paper is concerned with the modeling of neural systems regarded as information processing entities. I investigate the various dynamic regimes that are accessible in neural networks considered as nonlinear adaptive dynamic systems. The possibilities of obtaining steady, oscillatory or chaotic regimes are illustrated with different neural network models. Some aspects of the dependence of the dynamic regimes upon the synaptic couplings are examined. I emphasize the role that the various regimes may play to support information processing (...) abilities. I present an example where controlled transient evolutions in a neural network, are used to model the regulation of motor activities by the cerebellar cortex. (shrink)

Recent work has shown that segmentation underlies the patterning of the vertebrate hindbrain and its neural crest derivatives. Several genes have been identified with segment‐restricted expression, and evidence is now emerging regarding their function and regulatory relationships. The expression patterns of Hox genes and the phenotype of null mutants indicate roles in specifying segment identity. A zinc finger gene Krox‐20 is a segment‐specific regulator of Hox expression, and it seems probable that retinoic acid receptors also regulate Hox genes in (...) the hindbrain. The receptor tyrosine kinase gene Sek may mediate cell‐cell interactions that lead to segmentation. These studies provide a starting point for understanding the molecular basis of segmental patterning in the hindbrain. (shrink)