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Just 14 of the Many Facets of Stress

aaTintoretto_SanGiorgioDragoMRI scans have revealed that children of depressed mothers have a larger amygdala, a part of the brain associated with emotional responses, researchers from the University of Montreal explained in the Proceedings of the National Academy of Sciences (PNAS).

A new study published in the American Journal of Industrial Medicine reveals that the World Trade Center attacks affected the health of the New York City Fire Department (FDNY) resulting in more post-9/11 retirements than expected.

Researchers in the Hotchkiss Brain Institute (HBI) at the University of Calgary’s Faculty of Medicine have uncovered a mechanism by which stress increases food drive in rats.

Do you run when you should stay? Are you afraid of all the wrong things? An enzyme deficiency might be to blame, reveals new research in mice by scientists at the University of Southern California.

Constant bitterness can make a person ill, according to Concordia University researchers who have examined the relationship between failure, bitterness and quality of life.

Listening to music or sessions with trained music therapists may benefit cancer patients. Music can reduce anxiety, and may also have positive effects on mood, pain and quality of life, a new Cochrane Systematic Review shows.

Researchers at Harvard-affiliated McLean Hospital have found that those who believe in a benevolent God tend to worry less and be more tolerant of life’s uncertainties than those who believe in an indifferent or punishing God.

Knowing the right way to handle stress in the classroom and on the sports field can make the difference between success and failure for the millions of students going back to school this fall, new University of Chicago research shows.

An 8-week course of stress-reducing Transcendental Meditation resulted in a 50% reduction in PTSD (post-traumatic stress disorder) symptoms among Iraq/Afghanistan veterans, researchers reported in Military Medicine. The pilot study involved five veterans aged 25 to 40 years with PTSD symptoms – they had all served between 10 and 24 months and had been involved in moderate or heavy moderate combat.

When parents fight, infants are likely to lose sleep, researchers report. "We know that marital problems have an impact on child functioning, and we know that sleep is a big problem for parents," said Jenae M. Neiderhiser, professor of psychology, Penn State. New parents often report sleep as being the most problematic of their child’s behavior.

By helping people express their emotions, music therapy, when combined with standard care, appears to be an effective treatment for depression, at least in the short term, said researchers from the University of Jyväskylä in Finland who write about their findings in the August issue of the British Journal of Psychiatry.

Young adults whose mothers experienced psychological trauma during their pregnancies show signs of accelerated aging, a UC Irvine-led study found. The researchers discovered that this prenatal exposure to stress affected the development of chromosome regions that control cell aging processes.

A child who has a psychological adversity or a mental disorder that starts during childhood has a higher chance of developing a long-term (chronic) physical condition later on, researchers from the University of Otago, Dunedin, New Zealand reported in Archives of General Psychiatry. The authors explain that child abuse has been linked to a higher chance of adverse physical health outcomes.

Individuals with anxiety-related symptoms who self-medicate with drugs or alcohol have a higher risk of having a substance abuse problem and social phobia, researchers from the University of Manitoba, Winnipeg, Canada, revealed in Archives of General Psychiatry.

Discovery: A New Brain Pathway for Stress

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In many individuals, a major stressor activates a critical and previously unknown pathway in the brain that regulates anxiety in response to traumatic events. The amygdala, which is the emotional center of the brain, reacts to the stressor by increasing production of the protein neuropsin. The release of neuropsin activates a series of chemical events  that further stimulate amygdala activity, which in turn activates a gene that determines the stress response at a cellular level. Due to this gene activation, these individuals develop long-term anxiety and a typical anxious response to real or perceived stressors.

A study just published in the journal Nature for the first time clarifies the mechanism whereby, in certain individuals and not in others, the extracellular proteolysis triggered by fear-associated responses facilitates neuronal plasticity at the neuron–matrix interface. This process centers around the activity of the serine protease neuropsin, which is critical for stress-related plasticity in the amygdala. Neuropsin determines the dynamics of the EphB2–NMDA-receptor interaction, the expression of the “anxiety gene” Fkbp5 and the triggering of anxiety-like behavior. When faced with a stressor, individuals who are neuropsin-deficient show a much less frequent expression of the Fkbp5 gene and low anxiety. On the other hand, the behavioral response to stress in individuals who are rich in neuropsin shows a more frequent expression of the Fkbp5 gene and much more significant anxiety-related behavior. The researchers, consisting of a team of neuroscientists at the University of Leicester, UK, in collaboration with researchers from Poland and Japan, conclude that their findings establish a novel neuronal pathway linking stress-induced proteolysis of EphB2 in the amygdala to the development of an anxiety-driven response to stress.

Stress-related disorders affect a large percentage of the population and generate an enormous personal, social and economic impact. It was previously known that certain individuals are more susceptible to detrimental effects of stress than others. Although the majority of us experience traumatic events, only some develop stress-associated psychiatric disorders such as depression, anxiety or posttraumatic stress disorder… We asked: What is the molecular basis of anxiety in response to noxious stimuli? How are stress-related environmental signals translated into proper behavioral responses? To investigate these problems we used a combination of genetic, molecular, electrophysiological and behavioral approaches. This resulted in the discovery of a critical, previously unknown pathway. –Dr. Robert Pawlak, University of Leicester.

The study took four years to complete and it sought to examine the behavioral consequences of a series of cellular events caused by stress in the amygdala. They discovered that when certain proteins produced by the amygdala were blocked, either via medication or by gene therapy, the study subjects did not exhibit the highly anxious traits.

This is a significant discovery for the study and treatment of maladaptive stress responses that result in anxiety. By knowing which chemicals along the neuropsin pathway are present in the human brain at the moment of traumatic events, the researchers believe that it will be possible to design intervention therapies for controlling stress-induced behaviors and for the prevention and treatment of stress-related psychiatric disorders such as depression and posttraumatic stress disorder.

Stuck On Wide Open: Emotional Dysregulation

domesticviolenceEmotional regulation is perhaps the most dramatically visible and the prototypical feature of an individual’s personality. Many people appear to be mostly in command of their emotions at critical moments, while others appear to be particularly (and sometimes explosively) reactive to environmental and interpersonal challenges. In general, affective or emotional instability, inordinate bursts of anger, intense efforts to avoid real or perceived abandonment, and unstable interpersonal relationships point to an underlying attribute of emotional dysregulation. This set of features has been popularized as belonging to “drama queens,” or persons who tend to react to every situation in an overdramatic or exaggerated manner.

Sometimes, instances of emotional dysregulation in children (“acting out” behaviors) or in adults under the most severe stressors can be viewed as the only available response in circumstances in which overwhelmingly strong emotion must be expressed, such as in the context of an emotionally abusive family environment or in times of great personal upheaval.

DramaQueen1A large body of research suggests that alcohol use can increase underlying emotional disturbance and disrupt cognitive functions that are very important in emotional self-regulation. Support for this hypothesis comes from studies that find associations between alcohol use and short- and long-term emotional change. In the short term, alcohol can disrupt emotional stability by effectively removing barriers against violence, verbal abuse, and inappropriate behaviors. In the long term, alcohol dependence and addiction can create a false persona in which it becomes difficult if not impossible to distinguish between the individual’s genuine personality traits and those modified or instigated by alcohol use.

Emotional disorders, particularly when they are characterized by pervasive emotional dysregulation, are often characterized by high negative emotionality and low positive emotionality. A significant challenge in trying to downregulate negative emotions is to become less vulnerable to negative or distressing emotions, with the objective of increasing calmness and resilience in stressful situations.

To achieve better emotional regulation, biological change and contextual change are needed. Biological change is achieved by reducing individual reactivity to emotional stimuli. Even when this reactivity may be due to genetic dispositions (temperament) and early developmental experiences (nurture), most people can learn ways to better control their emotional expression. There is a combination of skills and interventions that is particularly helpful in promoting biological homeostasis and emotional stability. These include treating any underlying physical illness that may have a negative effect on mood, balancing nutrition and eating to replenish and maintain physical resources, staying off non-prescribed mood-altering substances, getting sufficient but not excessive sleep, and getting adequate physical exercise.

Contextual change refers to learning and practicing emotional resiliency, which is the ability to minimize negative effects of stressful events and situations, and to maximize the positive effects of positive outcomes and opportunities. The skill of resiliency is learned and reinforced by intentionally accumulating positive life events, i.e., making a conscious and deliberate catalog of what’s positive in one’s life and referring to it often until it is present and readily available in time of need. It also consists of developing practical skills that build a sense of generalized mastery and promote self-esteem, e.g., completing school, obtaining additional job training, taking an assertiveness course, and the like.

What Causes (And Cures) Emotional Dysregulation

The amygdala has been implicated in emotional dysregulation, aggressive behavior, and psychiatric illnesses such as depression. Anxiety disorders and dysregulation may be the result of too much activity in the amygdala and not enough activity in the prefrontal cortex (PFC), which is the executive center of the brain that sets boundaries of behavior and responds to criteria of calm, assertiveness, and emotional regulation.

BDNFStress, coupled with a genetic vulnerability, decreases the production of brain-derived neurotrophic factor (BDNF). BDNF is a protein that acts on the nervous system by helping the survival of existing neurons and promoting the growth and differentiation of new neurons and synapses. A reduction in BDNF production causes a thinning of neuronal structures, which can results in emotional disturbance. These structural changes make the prefrontal limbic governing system vulnerable to disruption and dysregulation. Thus, emotional stress, loss, or  other significant psychological factors cause the system to lose self-regulation.

Treatments such as antidepressant medications, lithium, electroconvulsive therapy, exercise, psychotherapy and good social support can reverse this process, increase the production of BDNF, renew neuronal growth, build more resilient self-regulating circuits, and return the individual to a healthy mood.

Disorders of Emotional Dysregulation

PTSD, or posttraumatic stress disorder, is characterized by very significant emotional dysregulation. Its sufferers experience unwarranted arousal—often caused by stimuli processed Depressed-Soldier-02outside of conscious awareness—and exhibit an exaggerated startle response, vivid intrusive thoughts, and flashbacks and nightmares related to past traumatic events. PTSD victims may frantically try to avoid physical or psychological reminders of their trauma, and may experience dissociative symptoms or emotional numbing. PTSD is a disorder of emotional dysregulation characterized by excessive fear, triggered by a severe and often life-threatening traumatic event.

Borderline personality disorder (BPD) is characterized by emotional dysregulation, the temporary but frequent inability to change or regulate emotional cues, experiences, actions, verbal responses, and nonverbal expressions. Individuals with BPD experience greater emotional sensitivity, greater emotional reactivity, and slower return to normal levels of arousal after intense stimulation.

Frontal lobe disorders, which have become rather common among combat survivors, are the product of traumatic brain injury and are characterized by emotional dysregulation, attention deficit, impulsivity, lack of inhibition,  poor insight, impaired judgment, and low motivation. These frontal-subcortical disorders can result not only from war zone trauma, but also from infection, cancer, stroke, and neurodegenerative disease. Explosive violence, often directed at family members, is a common occurrence, particularly in individuals in whom impulsivity, disinhibition, and emotional dysregulation are the most dominant features.

Finally, obsessive-compulsive disorder (OCD) is characterized by emotional as well as cognitive dysregulation, brought on by a disruption of both the “thinking” prefrontal and the “feeling” paralimbic networks.

In these and other disorders that feature emotional dysregulation, it is interesting to note that the anatomic structures that are affected have emotional as well as cognitive functions. This coincidence highlights once again the close interdependence of affective and cognitive operations in the human brain. We can’t feel deeply without thinking intensely, and vice versa.

Optogenetics Discovers Brain Anxiety Circuit

AmygdCingGyrusThe state of heightened apprehension and high arousal in the absence of immediate threat—commonly labeled as acute stress or anxiety—can be a severely debilitating condition. Over 28% of the population suffers from anxiety disorders that contribute to the development of major depressive disorder and substance abuse. Of all the structures of the limbic system, the seat of emotion processing, the amygdala plays a key role in anxiety, although by what exact mechanism still remains unclear. Newly published research carried out by a group of neuroscientists at Stanford University using the novel technique of optogenetics with two-photon microscopy has permitted a much closer exploration of the neural circuits underlying anxiety than ever before. The optogenetics approach facilitates the identification not only of cell types but also the specific connections between cells. The researchers noticed that timed optogenetic stimulation of the basolateral amygdala (BLA) terminals in the central nucleus of the amygdala (CeA) produced a significant, acute, and reversible anxiety-reducing effect. Conversely, selective optogenetic inhibition of the same projection resulted in increased anxiety-related behaviors. These results indicate that specific BLA–CeA projections are the critical circuit elements for acute anxiety control in the brain. The results were published in the March 17 issue of the scientific journal Nature.

A Closer Look at the Amygdala’s BLA and CeA Regions

BasolateralAmygdalaThe amygdalae (amygdaloid nucleus) are two identical almond-shaped brain structures located in each temporal lobe. Each amygdala receives input from the olfactory system, as well as from visceral structures. The amygdala in humans has been confirmed by functional MRI imaging to be the area of the brain that is best correlated with emotional reactions and plays a key role in the brain’s integration of emotional meaning with perception and experience. The emotional aspect of the response of the individual is passed on to the frontal cortex, where “decisions” are made regarding possible responses. In this way, the response of the individual can take into account the emotional aspect of the situation.

Additionally, the amygdala coordinates the actions of the autonomic and endocrine systems and prompts release of adrenaline and other excitatory hormones into the bloodstream. The amygdala is involved in producing and responding to nonverbal signs of anger, avoidance, defensiveness, and fear. The amygdala has been implicated in emotional dysregulation, aggressive behavior, and psychiatric illnesses such as depression. It has also been shown to play an important role in the formation of emotional memory and in temporal lobe epilepsy.

The basolateral amygdala, one of the two structures studied in the recent Stanford research, receives extensive projections from areas of the brain cortex that are specialized for recognizing objects such as faces in central vision. Extensive intrinsic connections within the amygdala
promote further coordination of sensory information.

Biological effects initiated by amygdala include increases or decreases in arterial pressure and heart rate, gastrointestinal motility and secretion, evacuation, pupillary dilation, piloerection, and secretion of various anterior pituitary hormones, especially the gonadotropins and
adrenocorticotropic hormone, which are key agents in the stress reaction. Interestingly, amygdala stimulation can also cause several types of involuntary movement, such as raising the head or bending the body, circling movements, occasionally rhythmical movements, and movements
associated with taste and eating, such as licking, chewing, and swallowing.

LimbicSystemGeographyThe findings also show the involvement of the amygdala’s CeA region in mediating threat-related anxiety and acute fear-related behavioral and hormonal responses. Earlier studies had shown that stimulation of this same area reduces snake fear and pituitary-adrenal activity and that CeA lesions resulted in decreased expression of threat-induced freezing. Additionally, the CeA region of the amygdala was reported as being significantly involved in the consolidation of contextual fear memory, i.e., what permits us to remember so vividly and persistently objects or situations that have caused fear in us in the past.

Stress and the Female Brain Advantage

drlouannbrizendineIn 1994, Louann Brizendine, a neuropsychiatrist at the University of California, established the Women’s Mood and Hormone Clinic in San Francisco—one of very few such institutions in the world—and focused her attention on the etiology and functioning of the female nervous system.

In 2007, she published The Female Brain as the culmination of her 20 years of research and a compendium of the latest findings from a range of disciplines. It is a fascinating and, in some ways, startling revelation of the most noteworthy particularities that characterize the human female brain.

Size Does Matter… and So Does Density

Women and men have very nearly the same number of brain cells, even though the female brain is about 9% smaller than men’s. This fact had been known for some time and had been, more or less jokingly, interpreted as meaning that women were not as smart. Dr. Brizendine reveals a much simpler explanation: women’s brain cells are more tightly packed into the skull.

To further dispel any notion of masculine brain superiority, she says, women have 11% more language and hearing neurons than men and a larger hippocampus, the area of the brain that is most closely associated with memory. Much more developed in female brains than male’s is also the circuitry for observing emotion on other people’s faces. Dr. Brizendine concludes that, when it comes to speech, emotional intelligence, and the ability to store richer and more detailed memories, women appear to possess a richer brain endowment and thus a natural advantage.

The amygdala in males, on the other hand, has far more processors than in females, which could explain men’s greater intensity in perceiving danger and their higher proneness to aggression. The male body is much quicker to mobilize to anger and take violent action in reaction to an immediate physical danger.

Are women not as capable of reacting to danger? Dr. Brizendine says that a woman’s brain is as capable to perceive danger or deal with life-threatening situations, but that it mobilizes the body’s resources in quite a different way. The female brain appears to be wired to perceive greater stress over the same event than a man’s. This greater arousal and more forceful stress reaction appears to be a natural way to ensure adequate protection against all possible risks to her children or family unit. Brizendine suggests that this ancestral reason may account for the way a modern woman may view unpaid bills as catastrophic and naturally perceive them more intensely threating to the family’s very survival.

[amtap book:isbn=0767920104]

MRI scans have pushed knowledge much higher by allowing the observation of the workings of the brain in real time. The brain lights up in different places depending on whether it is stimulated by love, looking at faces, solving a problem, speaking, or experiencing anxiety. What lights up, where and when, is different between men’s and women’s brains. Women use different parts of the brain and different circuits to accomplish the same tasks, including solving problems, processing language, and generally experiencing the world.

This is a fascinating book for the scientist and the novice alike, well worth reading. It is the Stresshacker Recommended selection for this month.

Stress Hardware Update: Limbic System 2.0

LimbicSystemGeographyThe term limbic system designates the entire neuronal circuitry and forebrain structures that control emotional behavior, motivational drives and the processing of present and past sensory experiences. The brain structures of the limbic system are located around the middle edge of the brain. Several limbic structures are involved in determining the affective nature of sensory inputs, i.e., whether the sensations are pleasant or unpleasant. The emotional qualities we attach to the input provided by our five senses are also called reward (when they are pleasing to us and therefore we crave more of them) or punishment (when they are unpleasant and therefore we seek to avoid them), or satisfaction or aversion. Neurobiological research on the functions of the limbic system dating back to its XIX century pioneer Pierre-Paul Broca (1861), later expanded by James Papez (1937), Giuseppe Moruzzi and Horace Magoun (1949), and Ross MacLean (1949, 1952) identified the “reticular” and “limbic” systems as regulating the energizing and expressive roles in the central nervous system.

The limbic system is comprised of numerous structures, the most important of which are the hypothalamus, the amygdala, the hippocampus, the cortex, the cingulate gyrus, the striatum, the pallidum, the thalamus, and Meynert’s nucleus basalis. Each of these structures performs a specific function, and often also serves to receive, transmit and amplify communication within the limbic system, with other areas of the brain, and with other parts of the central nervous system.

The Hypothalamus: The Central Autonomic Controller

A major component of the limbic system is the hypothalamus and its related substructures. The hypothalamus complex controls the internal state of the body, such as temperature, osmolality of the body fluids, appetite and thirst and the regulation of body weight. Despite its very small size of only a few cubic centimeters (which represents less than 1% of the brain mass), the hypothalamic complex has two-way communicating pathways with all levels of the limbic system and is the key structure for higher level coordination of autonomic and endocrine functions. There would not be a stress reaction, with its almost instantaneous activation of physical and psychological defense mechanisms, without the hypothalamus providing the critical signal activation.

The Amygdala: The CPU of Emotional Response

AmygdCingGyrusThe amygdala is a group of nuclei embedded in the anteromedial temporal lobe, which receives input from all five senses. It performs the analysis of form and color and facilitates the recognition of complex stimuli such as human faces. The amygdala can influence heart rate and blood pressure, gut and bowel function, respiratory function, bladder function, and many more instinctive physical reactions. It is in the amygdala and its connection to other limbic structures that the determination of the affective value of sensory stimuli (rewarding or aversive) is made and our mood (or feelings about something) is determined. Stimulation of the amygdala produces the defense reaction that prepares us for fight, flight or freeze, along with complex sensory and experiential phenomena, which may include fear, sensory hallucinations, feelings of deja vu, and memory-related flashbacks and nightmares. The amygdala receives neuronal signals from all portions of the limbic cortex and is the “central processing unit” in which the limbic system produces an emotional response to events, people and situations. The amygdala also interacts with higher brain regions that govern such processes as directed attention, declarative memory, and response inhibition (Davidson, Putnam, & Larson, 2000; LeDoux, 1995).

The Hippocampus: Memory Chips and Orientation

The hippocampus is a highly specialized region of the cerebral cortex, which along with surrounding areas of the parahippocampal gyrus is directly involved in memory processing and spatial orientation. The hippocampus provides the neural mechanism for association of different parameters that is necessary for the moment-to-moment incorporation of experience into our short- and long-term memory banks. Almost any type of input from the five senses causes activation of at least part of the hippocampus, which in turn distributes many outgoing signals to the anterior thalamus, to the hypothalamus, and to other parts of the limbic system, especially through the fornix, a major communicating pathway.

The Orbital and Medial Prefrontal Cortex: Food and Personality

PhineasGageThe cortical areas of the limbic system are divided into two interconnected networks with related but distinct functions. Many of these functions are related to food or eating (e.g., olfaction, taste, visceral afferents, somatic sensation from the hand and mouth, and vision), and neurons in the orbital cortex respond to multisensory stimuli involving the appearance, texture, or flavor of food. Therefore, the orbital and medial prefrontal cortex have the function of evaluating feeding-related sensory information and to stimulate appropriate visceral reactions. More importantly, damage to the ventromedial frontal lobe can produce dramatic behavioral changes, which suggests that the visceral reactions evoked through this cortical area are critical in evaluating alternatives and making choices. As the well-publicized 19th-century case of Mr. Phineas Gage’s accidental head impaling by a steel rod demonstrates, individuals with damage to the ventromedial prefrontal cortex have no problem with their motor or sensory function, their intelligence or cognitive function, but show devastating changes in personality and choice behavior.

The Cingulate Gyrus: The Cement of Society

Intriguing data and ideas have been proposed by several researchers seeking to identify specific functions of the cingulate gyrus. In what has been termed the affiliation/attachment drive theory, Everly (1988) has shown experimentally that the removal of the cingulate gyrus eliminates both affiliative and grooming behaviors. MacLean (1985) has argued that the affiliative drive may be hard-coded in the limbic system and may be the anatomical underpinning of the “concept of family” in humans and primates. The drive toward other-oriented behaviors, such as attachment, nurturing, affection, reliability, and collaborative play, which has been referred to as the “cement of society” (Henry and Stephens, 1977), appears to originate in this relatively small limbic system structure.

The Ventromedial Striatum, Ventral Pallidum, and Medial Thalamus

The nuclei of the ventromedial striatum are also related to reward and reward-related behavior, whereby they inhibit or suppress unwanted behaviors while allowing other behaviors to be freely expressed. The dorsolateral striatum and related areas of the globus pallidus appear to be involved in switching between different patterns of motor behavior, whereas the ventromedial striatum and pallidum may allow changing of stimulus–reward associations when the reward value of a stimulus has changed. These areas are examples of the complexity and redundancies built into limbic system structures that permit multiple iterations of signal transmission and reception, and a much more complex and refined analysis of sensory inputs from the five senses.

Nucleus Basalis (of Meynert)

The nucleus basalis of Meynert is a prominent group of large cells located in the basal forebrain, most of which are involved in the activation of acetylcholine or GABA neurotransmitters, indispensable in activation of the stress reaction and our defense mechanism when a physical or psychological threat is perceived. The magnocellular basal forebrain nuclei are well situated to modulate brain activity in relation to limbic activity.

Disorders of the Limbic System

Although lesions to limbic structures do not necessarily result in sensory or motor deficits, any loss of function in these structures is usually associated with a variety of psychological problems, including depression, bipolar disorder, obsessive–compulsive disorder, and schizophrenia.

Structural changes have been noted in the hippocampal formation, medial thalamus, and prefrontal cortex in schizophrenic subjects. Images obtained through positron emission tomography scans show that the amygdala, prefrontal cortex and medial thalamus are abnormally active in patients suffering from severe unipolar and bipolar depression.

The complete removal of the amygdala and other nearby structures in laboratory settings causes specific changes in animal behavior called the Klüver-Bucy syndrome, whose characteristic symptoms are a complete lack of fear of anything, extreme curiosity about everything, rapid loss of short-term memory, tendency to place everything in the mouth and sometimes even trying to eat solid objects, and a sex drive so strong that it leads to attempts to copulate with immature animals, animals of the wrong sex, or even animals of a different species. Although similar lesions in human beings are rare, afflicted people respond in a manner not too different from that of the affected animal.

When Stress Hurts: Central Nervous System

In establishing the connection between the onset of psychogenic pain and stress, it is important to notice that pain and stress share the same central nervous system (CNS) pathways and structures. In this second post in the series on the close association between psychological stress and psychogenic pain, we’ll take a look at these shared structures.

CNS Structures Mobilized by Pain and Stress

PendulumThe body’s response to pain engages a large number of CNS structures that are often the same as the ones activated by the stress reaction. The afferent pathways that carry pain signals connect to the thalamic nuclei and from there to the somatosensory, insular and anterior cingulate (ACC) portions of the brain cortex. A recent functional MRI (fMRI) study (Keltner et al., 2006) on the effects of pain expectation on pain transmission provides the best evidence for the activation of the rostral ACC (rACC), periaqueductal gray (PAG), and medial prefrontal cortex. This and other imaging studies provide evidence of a bidirectional pain pathway receiving input from the limbic system and the amygdala, converging on the PAG, traveling through the pontomedullar nuclei, and controlling spinal pain transmission neurons (Fields, 2000; Fields & Martin, 2001). As the authors of this study point out, “expectation for a higher intensity noxious stimulus increases subjectively experienced pain intensity in part through the action of a descending pathway that facilitates nociceptive transmission at and/or caudal to the region of the contralateral nucleus cuneiformis (nCF)” (p. 4442). The nCF, in humans and other primates, has a composition similar to the PAG and its neurons project directly into the rostroventral medulla, the hypothalamus and the amygdala, all structures directly involved in modulation of the stress reaction.

PMR_muscle-crampsLikewise, the body’s stress response engages a large number of the same CNS structures, specifically certain subregions of the hypothalamus such as the paraventricular nucleus (PVN), the amygdala, and the periaqueductal grey; and certain cortical brain structures, such as the medial prefrontal cortex and subregions of the anterior cingulate and insular cortices (Maier, 2003). These structures provide output to the pituitary and pontomedullar nuclei, which in their turn stimulate the body’s neuroendocrine secretions, as well as to the hypothalamic-pituitary-adrenal (HPA) axis, the endogenous pain modulation system, and the ascending aminergic pathways. The feedback controlling the stress response is provided by the serotonergic (raphe) and noradrenergic (locus ceruleus) structures and by the levels of glucocorticoids in the blood stream, which provide inhibitory impulses to the medial prefrontal cortex and to the hippocampus. Corticotrophin releasing hormone (CRH) is the fundamental chemical substances mediating the stress response, which is secreted by PVN, amygdala, and locus ceruleus neurons. Acute or chronic stress can temporarily or permanently modify the level of responsiveness and output of the CNS to stress (Bennett et al., 1998).

Sharing Pathways, Sharing Outcomes

With this significant convergence of pathways, neurochemical activity and CNS structure activation, it should come as no surprise that acute stress can provoke physical pain, often in the head, the muscles, and the abdominal region. Equally unsurprising is that pain, especially when sharp and unexpected, is in itself a cause of stress that mobilizes the body into immediate action (think of the hand that immediately goes to cover the cut or the burn). Continuous pain, of any origin, is inherently stressful. Continuous stress can be, and often is, manifested by otherwise unexplained (thus psychogenic) physical pain.

Previously in this series: When Stress Hurts: Psychogenic Pain

Next:

  • The Neurochemistry of Psychogenic Pain and Stress
  • Psychological Stressors and the Sudden Appearance of Psychogenic Pain
  • Fibromyalgia, Severe Headaches and Other Stress-Related Misery
  • Medical and Non-Medical Treatments for Stress and Psychogenic Pain

Something Needs to Be Done About Hostility!

Ginetto at Stresshacker.com Hostility is stressful, both ways. To giver and receiver alike, hostility metes out its toxic charge of badness. Far from being a true relief for frustration, pent-up anger, or unexpressed emotion, a sudden explosion of hostility merely releases a burst of energy and briefly discharges some muscle tension. Beyond these ephemeral effects, it is hard to find a good justification for hostility in everyday situations. So why is it so prevalent?

Two reasons account for hostility’s “popularity.” The first is the genetically programmed aggression instinct, which, in its proper setting and situation, can be useful (in a competitive physical sport like football), or downright vital (in combat situations, to fight off an aggressor, or in other situations of danger when a calm and relaxed demeanor would be clearly out of place). We can be aggressive and hostile by design, but we are also given a brain that helps mitigate the limbic system’s rage of emotions, and the amygdala’s watchfulness against aggressors, real or perceived as they may be.

The second reason for the pervasive presence of hostility is a misfiring of the very structures of the brain that are supposed to help us regulate it. Poor regulation of negative emotions can unleash hostility. Notoriously so, antisocial personalities have little to no self-regulation of hostility and most of the times this lands them in jail. Many more individuals, though, fall short of law-breaking hostility but still exhibit plenty of it in everyday situations (behind the wheel of their car, while waiting in line, with customer service people, with their spouses, children, friends) to make life more stressful for themselves and for anyone they come in contact with.

Steve Slater on Stresshacker.com At the other end of the spectrum, hostility, while present as a natural emotion, can be sublimated into a more productive and less threatening display of displeasure with someone or a situation.  Well-regulated hostility and aggressive instinct become assertiveness, standing up for one’s right, engaging in an passionate discussion. It can also sublimate into artistic pursuit, an all-out workout at the gym, or humor. A recent example of the latter was portrayed by JetBlue flight attendant Jeff Slater. Justifiably enraged by an unjustifiably aggressive passenger, Mr. Slater regulated down his hostility, expressed himself aloud on the plane’s PA system, grabbed a couple of beers, activated the emergency slide, slid down to the tarmac, ran for his car and drove home.

Hostility and (Bad) Health

Negative emotional states, such as anger and hostility, when they persist over time and become chronic, can negatively impact health. The risk to health comes through a number of mechanisms, including engaging in high-risk behavior (verbally provoking, physically attacking others), loss of social support (no one wants to be with a chronically hostile individual), and social isolation.

Chronic negative emotions also induce a semi-permanent activation of the stress reaction and cause sustained systemic inflammation, both of which increase the risk of disease. Research on hostility and aggressive personality has clearly established a link between these emotional states and heart disease, heart attacks, and cardiac-related mortality. Hostility not only contributes to a higher incidence and increased severity of heart disease, but is also related to symptoms of metabolic syndrome, including insulin resistance.

What Can Be Done?

Taking a page from Mr. Slater’s playbook, humor is one of the highest levels of sublimation that can be achieved in down-regulating aggression and hostility. Other forms of self-regulation of hostility (which incidentally are also ways of dealing with stressful situations in general) can be listed as follows:

  • Anticipation (the ability to anticipate the consequences of hostility and evaluate alternative responses)
  • Affiliation (turning to others for help and support, initiating a dialogue instead of a confrontation)
  • Altruism (taking into account the needs of others, and being able to contain rather than meet their aggression head on)
  • Humor (finding the amusing and the ironic in the situation)
  • Self-assertion (expressing feelings and thoughts directly and openly, but without resorting to verbal or physical violence)
  • Self-observation (reflecting on one’s own reactions and regulating them appropriately, before the explosion occurs)
  • Sublimation (channeling negative feelings into positive behaviors, i.e. taking it out on gym equipment, a good run, a distracting activity)
  • Suppression (intentionally avoiding catastrophic, negative and pessimistic thoughts that can lead to aggression).

Of Mel Gibson, Narcissus and Stress

mel-gibson-oksanaA sad pattern seems to be emerging: as Mel Gibson becomes distressed, some self-medication ensues, allegedly alcohol. The medication, instead of solving the problem, appears to merely loosen Mel’s inhibitions and he unleashes a now painfully public tirade laced with profanity, discrimination, and sexism. In many quarters, his behavior has been described as the epitome of narcissism. But is this really his problem? Let’s consider the story of Echo and Narcissus.

In the vicinity of Mt. Olympus, about 2,500 years ago, the sylvan nymph Echo fell in love with Narcissus. Narcissus was an uncommonly handsome and incredibly vain man who would live on beyond Greek mythology and become the eponym of self-centeredness. He rejected Echo’s love with such callousness and contempt that she died of a broken heart. Apollo, angered by Narcissus’ vanity and cruelty, cursed him to die without ever knowing human love. Not too long afterwards, as a thirsty Narcissus went to a pool of clear water and knelt beside it to drink, he saw his face reflected on the surface of the water and fell in love with it. Unable to reach the image in the water, Narcissus continued to stare at it forgetting everything else, and eventually died beside the pool.

From ancient tale to modern problem, the term narcissism today describes a mental disorder that is characterized by an excessive positive self-evaluation and near-total lack of consideration for others. As a personality type, a narcissist is prone to a grandiose evaluations of self, a constant preoccupation with success and power, an exaggerated sense of entitlement, and an exploitative approach to others. A narcissistic personality shows an enduring pattern of personal adjustment characterized by grandiosity, need for attention and admiration, and a lack of empathy. Individuals with this disorder believe that they are special and are excessively envious of others while being preoccupied with their own achievement and power.

Freud believed narcissism originated in childhood, making it particularly difficult to treat in adults. There is much controversy as to the core problem in narcissism. Some believe it may be primarily an emotional problem; others view it as a cognitive deficit, i.e. the narcissist’s inability to construct an accurate view of self. A third school of thought theorizes that a narcissist is cursed with an ‘‘empty’’ sense of self; yet another group argues that the narcissist may have a ‘‘disorganized’’ self.

The problem that originates all these theories as to the origin of narcissism is produced by the lack of accurate measurements of its impact and severity. Narcissistic people do not admit their problems when asked. When diagnosed, they are very reluctant to cooperate with the treating therapist. In fact, they are widely considered by clinicians as among the most intractable of mental health patients.

In the most recent large-scale research, Russ, Bradley, Shedler, and Westen (2006) have produced evidence that a clinical distinction may be made between grandiose narcissism, characterized by genuinely inflated views of self and a need-gratifying approach toward other people and relationships, and fragile narcissism, characterized by explicit grandiosity paired with feelings of inadequacy or self-loathing.

So where can we place Mr. Gibson along the continuum from normal self-evaluation to narcissism?  If there is narcissism in his personality, would it be the grandiose, or rather the fragile type? Without falling into the trap of long-distance diagnosis, a few comments can be made on his reported behavior. First, if there is self-medication with alcohol as has been reported, the something that is being medicated hurts, perhaps deeply, at the emotional level. Relationship problems, as they have been reported to exist, invariably cause emotional reactivity and chronic sympathetic arousal, i.e. chronic stress. The combination of stress and the disinhibiting effects of self-medication can produce a state of mind that exacerbates any feelings of entitlement, lack of empathy for others and an exploitative approach to problem-solving (a condition popularly known as an amygdala hijack).

It would seem that there is a match with Mr. Gibson’s recently broadcast telephone rants.

Stress, As Seen Through the Eye of Science

Bazille at Stresshacker.comWhen science looks at stress, the focus is on the body/mind interaction or, more precisely, on its psychophysiological mechanisms. Traveling back in time from our present condition to conception, we can see that our genes and the environment in which we grow up (in which our genes are expressed) determine how we respond to stress as adults. Our genetic and environmental differences (the nature or nurture of who we are) help explain how individuals exposed to the same stressful situation can have an entirely different reaction. Some can adapt successfully to the stressor (albeit not without discomfort), while others experience more severe immediate trauma and long-term emotional problems, such as PTSD.

During specific developmental periods, such as infancy, puberty, adolescence, adulthood, or maturity, certain stressors are almost certain to occur and are understood to be typical and appropriate to the process of maturation and change. The earliest such stressor is the effect of caregiving styles, which stems from the parents’ psychological state. An attentive and nurturing style produces vastly different effects on the child’s later adaptation to stress than a harsh, unforgiving or neglectful one. In adolescence, patterns of behavior and emotional reactivity—including the stress reaction—begin to crystallize and become fully set in early adulthood.

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Is Stress Entertainment?

Avatar at Stresshacker.com The rep is that stress is to be avoided. The reality is otherwise. Stress is avidly watched, read, and heard because, contrary to what we think we believe about it, stress is entertaining. Why?

The truth is, stress sells—in movies, books, quiz shows, talent shows, and crime scene dramas. Not always and not for everyone, to be sure, but in vast numbers of book plots, screenplays, TV storylines, in radio plays, and theater plays, stress reigns supreme.

The surface reason is that stressful situations, when they are happening to someone else as in most forms of entertainment, hold our attention. Peaceful, restful, and relaxing situations, when we watch them happening to someone else, generally do not. There is not much fun in reading about someone having a really quiet day when nothing much is happening, but isn’t it great to watch a-thrill-every-second action on the big screen? Indeed, there is a deeper, genetically programmed reason why stress can be fun.

What’s the Fun in Stress?

To understand what’s happening, we must step back and consider the mechanics of stress. When we perceive a threat (a risk, a danger, a challenge), our mind is instantly alerted by the stress reaction that we experience in the body. Most often, this consists of increased heart beat, elevated blood pressure, muscle tension, and a release of excitatory hormones into the blood stream (cortisol, epinephrine, adrenaline), plus a host of other biological changes that very quickly get us ready for action. Now, what is interesting here is that, in addition to mobilizing the body, the excitatory hormones also generate a certain amount of pleasurable sensations. Is this nature’s little joke, or what?

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Research News: PTSD, Attachment and Healing

Leutze_1851_WashCrossDelaware The number of suicides reported by the Army has risen to the highest level since record-keeping began three decades ago. Last year, there were 192 among active-duty soldiers and soldiers on inactive reserve status, twice as many as in 2003, when the war began. (Five more suspected suicides are still being investigated.) This year’s figure is likely to be even higher: from January to mid-July, 129 suicides were confirmed or suspected, more than the number of American soldiers who died in combat during the same period. The New York Times

What Is PTSD?

Posttraumatic stress disorder (PTSD) can occur after the trauma of experiencing or witnessing  threatened or actual death or serious injury, or other serious threat to the physical integrity of self or others, such as assault. This type of trauma is usually accompanied by intense fear, helplessness, or horror at the time of the event. Symptoms of reliving the trauma and avoiding any reminder of it often create significant distress and negatively affect the individual’s  interpersonal and occupational functioning. In the acute phase, PTSD symptoms can last up to three months after the event. When the symptoms persist longer, PTSD is said to be chronic. Often, symptoms do not begin immediately and they can be delayed for six months or more after the event. When inadequately treated, PTSD can have fatal consequences such as homicide and suicide.

Who Is Affected?

It is estimated[i] that 50%–90% of all people are exposed to at least one serious traumatic event during their lifetimes. However, only about 6%-8% develop PTSD and a third of those suffer a severe form of the condition.

What Are the Causes?

The mechanism by which some individuals are vulnerable to PTSD and not others has been variously hypothesized. The most prominent theories are:

  1. The biological model
    Information about external stimuli and their assessment is processed by the amygdala. Traumatic stressors produce an emotional reaction of fight, flight or freeze and significant increases in stress hormones. The hippocampus and medial prefrontal cortex mediate the final response of the individual in trying to cope with the traumatic event. This theory suggests that posttraumatic stress disorder occurs when there is a failure to regulate the activity of the amygdala, which results in hyper-reactivity to threat (what is often referred to as the amygdala hijack).
  2. The early childhood experiences model
    Most researchers have found that childhood trauma, chronic adversity, and family stressors increase the risk for PTSD in adulthood.
  3. The traumatic memory model 
    A theory that has gained prominence in recent years, it distinguishes between memories that are easily recalled and are associated with emotions related to the trauma and repressed memories that cannot be deliberately accessed and are associated with typical PTSD symptoms such as nightmares and flashbacks.
How Is It Treated?

Most treatments for PTSD consist of techniques that expose the individuals to imagined re-experiencing of the trauma under safe therapeutic conditions, an approach that dates back to the treatment of World War II veterans. This type of treatment includes extensive emotional processing and narrative reconstruction of traumatic events in psychotherapy session, and may also include daily home review of audiotaped sessions.

Other efficacious treatments are cognitive behavioral psychotherapy and eye movement desensitization and reprocessing (EMDR). These treatments also induce patients to consciously review (and thus reprocess) painful details of their traumatic experience in a therapeutically safe environment.

PTSD and Childhood Attachment

A recent study[ii] by Columbia and Cornell researchers suggests that childhood attachment problems may play a crucial role in the development of adult PTSD and that exposure treatment may not be the sole important treatment mechanism.

According to attachment theory, secure and insecure childhood attachment to the primary caregiver (most often the mother) has important consequences for adult functioning and psychopathology. The theory, developed by British psychologist, psychiatrist and psychoanalyst John Bolwby, suggested that the innate human drive to form attachments that elicit protective, caretaking behaviors from adults is a crucial aspect of healthy infant development. When the caregivers are available and responsive, the infant develops a secure attachment “base” that facilitates the child’s exploration of the world and relationships. When the caregivers are absent or uncaring, an insecure attachment style results, with consequences for adult self-esteem, perceived safety and interpersonal functioning.
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Stress Hardware Review: The Amygdala

AmidalaL

There are things I cannot do. I cannot watch my people suffer. I cannot sit when something must be done. I cannot judge those who are different. There are things I cannot do. Run. Hide. Ignore. There are things I cannot do. But there are certainly things I will do!

Padmé Amidala in Star Wars: Clone Wars

One of the most important structures of the brain’s limbic system is the amygdala, which in Queen Amidala’s imaginary brain produced behavior that was characteristically cool and aloof at times, forceful and passionate at others, but always kept in balance by poise and careful deliberation. An exemplar of good stress management.

amygdala The human amygdala is an almond-shaped double  complex (one on each side of the brain) of multiple small nuclei located immediately beneath the cerebral cortex of the medial anterior pole of each temporal lobe. It has abundant bidirectional connections with the hypothalamus as well as with other areas of the limbic system. The amygdala is understood to be a behavioral awareness area that operates at a semiconscious level. It also appears to project into the limbic system one’s current status in relation to both surroundings and thoughts. The most important function of the amygdala is to make the person’s behavioral response appropriate for each occasion… or not, as the case may be.

What specific stress behaviors are directly regulated by the amygdala? We can only infer, as the Maker did not provide a user manual, through observing what happens when the amygdala is accidentally or intentionally removed. Take the jump to find out.

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