Stress

Definitions of terms: stressor, stress response, allostasis, allostatic load: 

Stressor: any stimulus that perturbs the physiological and psychological integrity of an organism  

Allostasis: process of achieving stability through change (stable functioning of our systems, response from our Cns and Ans) 

Allostatic load:  

• Physiological cost of adaptation  

• Want it to be low as possible, least amount of stress-on-stress response system 

Types of stressors: 

• Physical- interaction with predator-prey, physical illness  

- Acute  

- Chronic  

• Psychological – grief and loss, caregiving, school and career  

• Social – social isolation, bullying, societal stressors: racism, inequality, poverty, digital world related stress 

What is the stress curve? : 

Valance of Stress: How strong is the stressor?  

• Eustress- at a good point and responding appropriately  

• Distress- cannot function, memory impaired, burn out 

For each step of the stress response be able to  

identify brain areas (and their function), neurotransmitters, and/or hormones that are involved 

Stress and the Brain: Amygdala  

• The brains alarm center  

• Activates the sympathetic branch of the ANS (fight or flight) 

• Inhibitory tone: it is sending out signals to dappen responses from other areas  

• Hyperactive – its sending message along projections causing release CRH and sending info to hippocampus and prefrontal cortex  

Stress and the Brain- Hippocampus  

• Regulating stress response in HPA 

• High concentration for glucocorticoid receptors  

• Sensitive to stress  

• It is unique because it can generate new neurons in the hippocampus 

• Reduced HPA negative feedback/ Memory Impairment 

Stress Response: Threat Response  

Encounter the stress: 

1. The amygdala (alarm center) 

2. Once threat is recognized then get info from hippocampus giving us contextual info 

3. Decision making in the prefrontal cortex: Encountering some type of threat and figuring out what type of response to do 

Critical periods for stress responsiveness 

What are the effects of stress at each critical period: 

Critical Periods in Utero: 

• Stress hormones from the mother (can pass through placenta and have effect on the baby) 

Maternal stress associated with: 

• Shorter gestational age (born preterm) 

• Increase in preterm births  

• Low birthweight (not a good weight can impact ability to develop as you should) 

• Small size for gestational age (smaller than they should be) 

• Dutch famine 1944-1945 

• Children were born to those moms had higher rates of schizophrenia, depression and anxiety 

Early Life: 

• Early life stress can increase the risk of developing psychiatric disorders 

Maternal care by rats 

• Lick and grooming  

• More glucocorticoid in the hippocampus 

Critical Periods: Adolescence and Aging 

Adolescence 

• Hormones 

• Plasticity 

• Social changes  

Aging 

• Decrease in Hippocampal function  

• Hyper-reactivity to stress 

• If you are exposed to small stressor, it becomes a big deal and hard to get past it  

Know the factors that can influence stress response: 

• Perception of stressor – how do we initially perceive this stressor as a threat?  

• Appraisal – we think it is a threat, what kind of threat? How long do we think its going to be a threat? 

• Reappraisal – learn to do this (rethinking what the stressor or response to it means) 

• Predictability- predict that there is going to be a stressor in your life, you can plan for it (Ex. Plan for an exam), the more you plan for stressor the better the outcome  

• Controllability- Control over a stressor is going to reduce the negative consequences  

• Social support- social buffering. If you are with someone else and are experiencing a stressor, stress response is going to reduce. Be able to recover more quickly than if experiencing it by yourself. 

What types of things can alter our resiliency to stress: 

Alter resiliency?  

• Exercise 

• Meditation 

• Social support 

Clinical implications: 

Know typical symptoms: 

Allostasis  

• Process to restore homeostasis  

• Adaptation  

Allostatic load  

• Physiological cost of adaptation 

• Want it to be low as possible, least amount of stress-on-stress response system  

Mood Disorders: 

• Distorted inconsistent emotional state that go through time and interferes with your ability to function  

• Acute stress or chronic stressor and increase in mood disorders  

Anxiety Disorders 

• Intense and excessive symptoms of anxiety and worry that last persistently 

Relationship between stress and immune function - know evidence that supports 

Following the inverted-U pattern, acute stress seems to enhance immune

responses while chronic stress has a suppressive effect (prevent)