external image student-stress.jpgexternal image 01stressed.png


Team members:

Ann Chow 3384600

Naomi Hung 3372928

Gia-Yen Luong 3419256

Alison Young 3384605


Stress article

Introduction

This page investigates the neuroscience behind the article ‘Six ways to tame your stressed-out brain’ by Eileen Chadnick published in The Globe and Mail on 8th August 2013. The article explains what stress is and some strategies for managing stress.

The article was of particular interest because we all experience stress in our day-to-day lives. While moderate stress can motivate us, prolonged stress causes detriment to health and disrupts daily life. Research has shown that 1 in 7 Australians experience severe stress levels, particularly students (Casey, 2012). ‍Therefore, it is important for us to understand the mechanisms of stress and methods we can employ to manage or alleviate its effects.


Neuroscientific context

A. What is Stress?


Stressors are experiences that pose emotional and physiological challenges which trigger the stress responses necessary for survival. This response involves the activation of the autonomic nervous system and hypothalamus-pituitary-adrenal axis (HPA) (McEwen, 2007). The fight-or-flight response is commonly used to describe the behavioural and physiological changes involved in the response (McEwen).

Autonomic Nervous System (ANS)


The automatic nervous system maintains homeostasis. It has two divisions: the sympathetic and parasympathetic. Under stress, the sympathetic division is activated (Bear, Connors & Paradiso, 2007).



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Figure 1: Physiology of the stress response (The American Institute of Stress, 2013)



Amygdala

Figure 2: The Brain
Figure 2: The Brain


The amygdala receives sensory information from the hypothalamus and cortex. It is responsible for the fear response, stimulating the release of CRH (Bear, Connors & Paradiso, 2007).

Hippocampus


The hippocampus receives information from the cortex and can inhibit the release of CRH to stop the stress response (Bear, Connors & Paradiso, 2007).




prefrontal.jpg
Figure 3: Prefrontal regulation under non-stress condition (Arnsten, 2009)

Prefrontal cortex

The prefrontal cortex regulates cognitive ability (Arnsten, 2009). While the ventral medial prefrontal cortex (vmPFC) regulates emotion, the dorsal lateral prefrontal cortex (dlPFC) regulates thought and action. The right inferior prefrontal cortex (rIPFC) is responsible for suppressing inappropriate responses and the ventral medial prefrontal cortex connects with hypothalamus and hippocampus to perform emotional responses, such as fear responses.

The prefrontal cortex, amydala and hippocampus are interconnected to effect the stress response (McEWEN, 2007).








Hypothalamus-Pituitary-Adrenal axis (HPA)


When the parvocellular neurosecretory neurons in the paraventricular nucleus (PVN) of the hypothalamus receive stress input, corticotropin-releasing hormone (CRH) is secreted. CRH is released to the anterior pituitary gland, where adrenocorticotropic hormone (ACTH) is secreted. ACTH binds to a receptor in the adrenal gland and cortisol is released (Bear, Connors & Paradiso, 2007).

Figure 4: The HPA axis
Figure 4: The HPA axis

Cortisol causes the body to adapt to the stressful environment by using reserved energy, increasing the activity of the cardiovascular system and suppressing the immune system (Bear, Connors & Paradiso, 2007). The amygdala is activated and the prefrontal cortex is impaired, which results in decreased performance in cognition and judgment (Arnsten, 2009). Moreover, activation of the HPA axis lowers the level of serotonin (5-HT), which impairs the function of the digestive system (Lanfumey et al.,1999).

Oxytoxin is synthesised in the hypothalamus and transported to the posterior pituitary gland. When the neurosecretory neurons are stimulated, oxytoxin is released into the bloodstream, lowering the stress response and reinstating homeostasis. (Bear, Connors & Paradiso, 2007).


B. How Can We Cope with Stress?

Due to the prevalence of stress, various management strategies have been formulated. We now investigate some of these strategies.

i) Pause, Focus, Notice and Name it

Mindfulness Meditation (MM) has been increasingly integrated into psychotherapeutic programs and has been shown to have numerous benefits on psychiatric, functional somatic and stress-related symptoms (Hölzel et al., 2011). It involves the subject focusing their attention on body sensations, emotions and thoughts from a non-judgemental perspective. MM has reportedly produced high levels of calm and relaxation due to increased parasympathetic activity and decreased sympathetic activity.

MM may involve focusing on the internal, often sensory, experiences of breathing, emotions and/or other body sensations or focusing and sustaining attention on one subject and returning back to it if the mind wanders (Hölzel et al., 2011). It was found that during focused breathing and attention regulation, the rostral anterior cingulate cortex (rACC) and dorsal medial prefrontal cortex (dmPFC), along with subcortical structures, the hippocampus and caudate, were active. The activation of these neural correlates posits important information on how stress is regulated, as the rACC and dmPFC are responsible for resolution of emotional conflict. While the dmPFC detects the ext
ent of emotional conflict in the amygdala caused by stressors, the rACC resolves this conflict by inhibiting amygdala activity (Dickenson, Berkman, Arch & Lieberman, 2013; Etkin et al., 2006).


rACC amyg dmPFC.png
Figure 5: Interactions of neural correlates in mindfulness medtation practice







rACC.png
Figure 6: Brain areas involved in mindfulness meditation practice (Thayer, Ahs, Fredrikson, Sollers III & Wager, 2012)














The value of purposeful breathing is shown by Vlemincx, Taelman, Diest and Van de Bergh (2010) where sighing provided relief and restored the respiratory variability caused by stress to a stable rhythm. Breathing is regulated by respiratory centres in the brain stem involving input from central and peripheral chemoreceptors and vagal afferents of pulmonary stretch receptors for generating central rhythm and patterns of respiratory bursts. The input of cortical structures regulates the behavioural control. When autonomic control is overridden by behavioural influences, such as stress, there is excessive random variability in breathing. In this study, it was shown that sighs acted as general psychophysiological resetters. The breathing system was reset to a steady state, showing the homeostatic role of sighs.


The Prefrontal Cortex

When stress is encountered, coping processes are activated to reduce the effect of the aversive events. This often involves behavioural and psychological effort. Coping strategies are either problem-solving based, intended to engage in action to alleviate the aversive situation, or emotion-focused, aimed at reducing the emotional consequences of the aversive stimulus (Maier & Watkins, 2010). Maier and Watkins also mentioned that the dorsal raphe nucleus (DRN), serotonin (5-HT) and ventral medial prefrontal cortex (vmPFC) play a role in controlling stress. It was found that the DRN sends 5-HT to the amygdala and causes changes in the stress response.

According to Maier and Watkins (2010), the vmPFC mediates stress control and inhibits the stress response. The neuronal projections from vmPFC synapse with GABAergic interneurons in the DRN, resulting in inhibition of 5-HT release (Jankowski & Sesack, 2004, as cited in Maier & Watkins, 2010).

Inescapable Stress (IS) induces a greater activation of DRN 5-HT neurons than Escapable Stress (ES). This leads to greater 5-HT release. Studies have found that when an aversive stimulus is presented and there is a need to control stress, the projection from vmPFC to the DRN is activated (Baratta et al., 2009, as cited in Maier & Watkins, 2010). Therefore, vmPFC controls the inhibition of DRN activity and controls the stress response.


flow diagram_vmPFC.JPG
Figure 7: A flow diagram showing vmPFC in stress controllability.


A study by Varela, Wang, Christianson, Maier and Cooper (2012) found that ES exposure increases the reactivity of deep layer pyramidal cells of the prelimbic (PL) medial prefrontal cortex (mPFC), increasing rate and amplitude of action potentials (AP). However, no observable changes were found after IS exposure. The changes in ES exposure increased the responsiveness of neurons even with subthreshold excitatory input, leading to the ease of AP initiation and release of neurotransmitters, shown in Figure 8. Accordingly, acute and long-lasting behavioural resilience can be induced by exciting the mPFC. This excitation can be achieved by exposure to ES before IS. It allows for the activation of PL-DRN projection, inducing behavioural immunisation (Baratta et al., 2009, as cited in Varela et al., 2012).

flow diagram_ES effect.JPG
Figure 8: A flow diagram showing the dvelopment of behavioural resilience from the activation of ES exposure.


ii) Organise and Visualise

It has been found that the right and left hemispheres are involved in processing different information, for example: negative and positive affects and visual information from the left and right visual field (Hecht, 2010).

The Right Hemisphere‍ and Left Hemisphere

Hecht (2010) stated that the right hemisphere is more sensitive to fear-provoking stimuli than the left hemisphere, supported by research (Kimura, Yoshino, Takahashi & Nomura, 2004, as cited in Hecht, 2010), where fearful images shown to the left visual field caused elevated autonomic physiological response. Hecht mentioned a study showing that presentation of aversive stimuli to the right hemisphere through the left visual field increased cortisol secretion but not in the right visual field, i.e. the left hemisphere. Hence, the right hemisphere has shown to be more attuned to responding to stress inducing stimuli.

On the contrary, a study conducted by Grimm et al. (2008) found that reduced activity in the left dorsolateral prefrontal cortex (DLPFC) is correlated with emotional judgment, while hyperactivity in the right DLPFC is related to attention to emotional judgment. The left DLPFC in participants without MDD is negatively correlated with positive emotional valence. However, participants with major depression showed positive correlation, meaning emotionally positive stimuli are associated with less activity in the left DLPFC and the stimuli were rated less positively. There is also evidence supporting that positive stimuli do not stimulate the left DLPFC.


iii) Connect


A non-clinical option for alleviating stress is interacting with our friends and seeking moral support. Several studies have investigated the significance of this and have found an interaction between social support and oxytocin.

Oxytocin is a neuropeptide synthesised in the paraventricular and supraoptic nuclei of the hypothalamus and projects to the posterior pituitary before being released into the bloodstream (Heinrichs, Baumgartner, Kirschbaum, & Ehlert, 2003). It is released simultaneously with the activation of the HPA to attenuate biological-stress induced response and prompt behaviours such as looking after offspring or seeking social contact (Neumann, 2002; Taylor, 2006). In an animal study, Neumann found that blocking oxytocin action significantly increased HPA axis activity. This suggests that oxytocin, normally released in the PVN at rest, has an inhibitory role on ACTH secretion.

Research in humans has shown that there is an interaction between positive social support and increased levels of oxytocin, where together they can suppress cortisol and promote calm. Heinrichs et al. (2003) found that male participants exposed to stress after receiving a dose of oxytocin and being subjected to social support had the lowest levels of cortisol, and a high level of calmness post-stress compared to those who were subject to neither or one of those conditions.




Heinrichs graph.png
Figure 9: The mean salivary free cortisol concentrations in response to psychosocial stress in male participants. Exposure to the stressor is the shaded section of the graph. (Heinrichs et al, 2003)


Analysis

Target audience and pitch

The article was published in The Globe and Mail. The Globe and Mail is a Canadian national newspaper, which covers news and many social interest issues, such as this one. This article is aimed at average people who encounter stress at work or in everyday life. The article is not intended to be read by people who have specific knowledge about stress or neuroscience. This is obvious because the content is delivered in plain English, with colloquialism. The article uses a familiar example, an office scenario, and is written directly to the reader, increasing its accessibility.

As this was not intended to be read by experts, the information is unbiased and simple. The authors intended to provide help and advice to the average person.


Analysis of Neuroscientific Content

“Blame it on the Amygdala”


The article explains that stress is due to the amygdala reacting to “detect and protect”. To an extent, this is accurate, particularly when framed in a way that accessible to readers. While the explanation is not given in detail, it is sufficiently informative for lay people to understand and is not incorrect, as the amygdala plays a role in detecting and responding to emotional stress.

“Pause, Notice and name it, Focus”

The Prefrontal Cortex and Mindfulness

The first three coping strategies offered by the article are Pause, Notice and Name, and Focus.

The article claims that pausing provides a "buffer" to stress, and that counting up to 10 or breathing deeply can reduce stress levels. This advice is valid, as demonstrated by Vlemincx et al. (2010) in their sighing study. When pausing to count or take a break, the individual inadvertently regulates their breathing. By taking deep breaths, they are doing so intentionally, to the same effect of restoring cortical control. This restores the homeostatic pattern of breathing, reducing stress.

The article explains that noticing and naming the feeling of stress and focusing on the task at hand engages the prefrontal cortex, allowing for reflective thinking. The article could be referring to the benefits of mindfulness meditation, demonstrated by Holzel et al. (2011) and Dickenson et al. (2013). In recruiting higher cortical structures, there is greater executive control of the autonomic response, reducing the feeling of being stressed. However, the article states that mindfulness has the effect of increasing reflective thinking. This is not yet supported by research.

The article’s reference to the stressful effect of multitasking could be referring to the detraction of focus from a single task, which could cause the prefrontal cortex to become overwhelmed and lose control of the autonomic response. However, there is currently no research to support the article’s reference to reflective thinking or multitasking. It could be that in making the information accessible and reassuring readers, the author compromised some precision.

“Organise and Visualise”

The Left and Right Hemispheres

The article states that making organising can reduce the feeling of stress, due to the effect on the left hemisphere. There is currently little research to support this claim. The calming effect the article refers to could be due to the recruitment of the prefrontal cortex, as mentioned above.

The article specifies that readers should employ visualisation. The Hecht (2010) study indicates that the right hemisphere is more sensitive to visual fear stimuli than the left. The article is correct in advising readers to visualise calming images as these could have a "calming effect" on the right hemisphere. However, the effect of this on the stress level, which is mediated by both hemispheres, is questionable. It could have the effect of reducing the overall level of fear and stress, but this has not been proven.

The article could be referring to the type of information processed in the right hemisphere. While it cannot be identified whether the special sensitivity of the right hemisphere to fearful stimuli is employed, its general receptive nature in regard to visual information could assist prefrontal control by visual means. In this way, the article is accurate in advising individuals to utilise this specific function of the right hemisphere.

“Connect”

Oxytocin and social interaction

The article states that social interaction increases oxytocin, which has a "calming effect".As indicated by Henrichs et al. (2003), oxytocin does suppress cortisol and reduce stress. However, research cannot determine whether social support increases levels of oxytocins, or whether the two are independent of each other.

In the Henrichs et al. (2003) study, participants were presented with both oxytocin and social support before the stressor, so it is uncertain whether social support and oxytocin presented after the stressor is effective in reducing stress.

Therefore, it is questionable whether oxytocins can be increased by social interaction alone, and whether either has an effect if applied after the stressor.

Overall quality of information

The information provided in the article is generally accurate. While the information is not specific, the advice given is correct and can be effective. As this article was written for ordinary people, it cannot be expected that all the details of the neuroscience are provided accurately.

Therefore, the article was written in accordance with current understanding of neuroscience in an appropriate form for its target audience.


Appendix

i) Selection and Search strategy

Throughout the process our group has been very democratic; selection of topic, delegation of tasks, researching and writing the wikipage have been divided evenly between group members and decisions were made as a group. The selection of our topic involved all members doing individual research to find an interesting topic, bringing all these ideas together and discussing which topic would be most appropriate, and interesting for this project. We chose this media item as it covered some content which was introduced in lectures and tutorials, but was also challenging in that it investigated further areas of neuroscience which we were not familiar with and were interested to research.

We searched the articles through Google Scholar and searched through the UNSW library website. We also used the PsycINFO database as these search tools provided us with the most accurate and reliable information. We searched the articles by typing in keywords in the search box, such as "right hemisphere and stress", "prefrontal cortex and stress" and "oxytocin and stress". We also looked at some related articles recommended by the site. We decided which resources to use based on the content and aim of the study presented in the articles. We first looked at articles that provided us with a brief idea of what the topic is about, such as how the right hemisphere is related to stress, and from that we looked for studies that supported these ideas as well as those which discovered included new ideas.

We searched for articles related to the coping strategies suggested in the article: right and left hemispheres, prefrontal cortex, oxytocin and social interaction and multitasking. We did not put much emphasis on what stress is as we did not want to overlap with lecture content.


ii) Summarised comments

Strong points evaluated

The introduction and background information are concise. The analysis was well written and in depth. The scientific context is well supported by recent research and the studies were well cited.

Areas that need improvement

Scientific Context

The section can be improved by using figures to explain the ideas and writing in a simple and concise manner. This was addressed by proofreading and editing the paragraphs. Moreover, it was suggested that figures and diagrams can be used to explain some of the concepts. Flow diagrams and images were added to explain what stress is, how the vmPFC controls stress response and the impact of ES.

One suggestion made was to introduce the strategy, in terms of what it involves, before explaining the neurobiological mechanism. However, as the strategy has already been explained in the article, we decided not to include that in the wiki page.

Another suggestion was to expand on the explanation for stress. We did expand to an extent but not much because Dr. Vickery warned us not to overlap with the lecture content. Therefore, we have decided not to put too much emphasis on explaning what stress is.

Analysis

It was said that the analysis did not summarise how accurate the presented information was, did not evaluate if the strategies work and did not clearly state whether there is evidence to support the strategies. It was also recommended to provide more definitive comments on the article’s quality. In response to this, a few changes were made to make the section more concise and to emphasise the analytical nature of the section.

As our focus is the neural mechanism associated with the strategies, we decided not to include studies investigating whether the specific strategies do work or not, but included more information about the neuroscientific mechanisms we thought the article was referring to in each recommended strategy.

Overall

All four reviewers mentioned that the page lacked structure and the paragraphs needed to be linked better, especially in the scientific context section. This issue was addressed by rearranging the paragraphs into subheadings according to the suggested strategies in the article rather than the different neuroscientific mechanisms.

It was also mentioned that there were minor typos and grammar mistakes, these were corrected by proofreading the whole passage.


References

The American Institute of Stress. (2013). Daily Life Stress. Retrieved September 21, 2013, from http://www.stress.org/daily-life/

Arnsten, A. F. T. (2009). Stress signalling pathways that impair prefrontal cortex structure and function. Nature Reviews Neuroscience, 10(6). 410-422.

Bear, M. F., Connors, B. W. & Paradiso, M. A. (2007). Neuroscience Exploring the Brain (Third Edition). Baltimore, MD: Lippincott Williams & Wilkins.

Casey, L. (2012). Stress and well-being in Australia in 2012: A state-of-the-Nation Survey. Australian Psychological Society. 1-38.

Dickenson, J., Berkman, E., Arch, J. & Lieberman, M. D. (2013). Neural Correlates of Focused Attention during a Brief Mindfulness Induction. Social Cognitive and Affective Neuroscience, 8. 40-47.

Etkin, A., Egner, T., Peraza, D. M., Kandel, E. R. & Hirsch, J. (2006). Resolving Emotional Conflict: A Role for the Rostral Anterior Cingulate Cortex in Modulating Activity in the Amygdala. Neuron, 51(6). 871-882.

Grimm, S., Beck, J., Schuepbach, D., Hell, D., Boesiger, P., Bermpohl, F, … , Northoff, G. (2008). Imbalance between left and right forsalateral prefrontal cortex in mjor depression in linked to negative emotional judgment: An fMRI study in severe major depressive disorder. Biological Psychiatry. 63(4). 369-376. doi: 10.1016/j.biopsych.2007.05.033

Hecht, D. (2010). Depression and the hyperactive right-hemisphere. Neuroscience Research, 68, 77-87. doi: 10.1016/j.neures.2010.06.013

Heinrichs, M., Baumgartner, T., Kirschbaum, C. & Ehlert, U. (2003). Social Support and Oxytocin Interact to Suppress Cortisol and Subjective Responses to Psychosocial Stress. Society of Biological Psychiatry, 54. 1389-1398.

Hölzel, B. K., Lazar, S. W., Gard, T., Schuman-Olivier, Z. S., Vago, D. R. & Ott, U. (2011). How Does Mindfulness Meditation Work? Proposing Mechanisms of Action from a Conceptual and Neural Perspective. Perspectives on Psychological Science, 6(6). 537-559.

Lanfumey, L., Pardon, M. C., Laaris, N., Joubert, C., Hanoun, N., Hamon, M. & Cohen-Salmon, C. (1999). 5-HT autoreceptor 1Adesensitization by chronic ultramild stress in mice. NeuroReport, 10(16). 3369-3374.

Maier, S. F. & Watkins, L. R. (2010). Role of the medial prefrontal cortex in coping and resilience. Brain Research,1355, 52-60. doi: 10.1016/j.brainres.2010.08.039

Malberg, J. E. & Duman, R. S. (2003). Cell Proliferation in Adult Hippocampus is Decreased by Inescapable Stress: Reversal by Fluoxetine Treatment. Neuropsychopharmacology, 28(9). 1562–1571.

McEwen, B. S. (2007). Physiology and neurobiology of stress and adaptation: central role of the brain. Physiological Reviews, 87, 873 -904. doi: 10.1152/physrev.00041.2006

Neumann, I. D. (2002). Involvement of the brain oxytocin system in stress coping: interactions with the hypothalamo-pituitary-adrenal axis. Progress in Brain Research, 139. 147-162.

Taylor, S. (2006). Tend and Befriend: Biobehavioral Bases of Affiliation under Stress. Current Directions in Psychological Science, 15(6). 273-277.

Thayer, J. F., Ahs, F., Fredrikson, M., Sollers III, J. J. & Wager, T. D. (2012). A meta-analysis of heart rate variability and neuroimaging studies: Implications for heart rate variability as a marker of stress and health. Neuroscience and Biobehavioral Reviews, 36. 747–756.

Varela, J. A., Wang, J., Christianson, J. P., Maier, S. F., & Cooper, D. C. (2012). Control over stress, but not stress per se increases prefrontal cortical pyramidal neuron excitability. The Journal of Neuroscience, 32(37), 12848-12853. doi: 10.1523/JNEUROSCI.2669-12.2012

Vlemincx, E., Taelman, J., Diest, I. V. & Van de Bergh, O. (2010). Take a Deep Breath : The Relief Effect of Spontaneous and Instructed Sighs. Physiology and Behavior, 101. 67-73.




Topic: Stress

Team members:
Ann Chow 3384600
Naomi Hung 3372928
Gia-Yen Luong 3419256
Alison Young 3384605

Stress article

You need to be a little careful here not to overlap too much with the stress lectures that you've had.
I think if you try and evaluate some or all of the six points in [[#|the article]], that should be both interesting and distinct. That probably shifts the focus of your content stuff more to right brain/left brain issues or multi-tasking or social interaction rather than "stress" itself.

Approved


[[#|Jobs]]:
Task
Person responsible
Deadline (for group)
Introduction
Ann
Wednesday 4/09
Neuro Content (1) – what stress is
Alison
Wednesday 4/09
Neuro Content (2) – [[#|how to deal]] with stress
Naomi
Wednesday 4/09
Analysis
Gia-Yen
Wednesday 4/09
Appendix
Everyone
Friday 6/09
Editing of first draft
Everyone
Friday 6/09

Date
[[#|Event]]
Friday 9/08
First meeting, [[#|complete]] work plan
Monday 12/08
Work plan, group, topic due
Monday 2/09
Finish draft and compile
Monday 9/09
Draft due
Monday 16/09
Provide comments (done individually)
Monday 16/09
Second draft and compile
Monday 23/09
Final project due

Meetings: Minutes of group meeting.docx
[[#|Photos]] of [[#|the meeting]]: photo 1, photo 2

Next Meeting: 6th September, 2013