Physiology of Behavior: Stress and Anxiety Disorders

This set of flashcards covers key concepts, history, mechanisms, treatments, and effects of stress, PTSD, anxiety disorders, and OCD as presented in the lecture.

What is stress?

A physiological reaction caused by the perception of aversive or threatening situations.

Who introduced the term 'fight or flight'?

Walter B. Cannon in the 1920s.

What was Hans Selye's contribution to the concept of stress?

Introduced the term 'stress' and identified the General Adaptation Syndrome.

What physiological changes occur during the fight-or-flight response?

Increased blood pressure, elevated blood sugar, and dilated pupils.

What is the role of the Sympathetic Adrenal-Medullary system (SAM)?

Releases epinephrine and norepinephrine to stimulate fight-or-flight response.

What does the Hypothalamic-Pituitary-Adrenal Axis (HPA) release?

Releases glucocorticoids, primarily cortisol.

What is the main effect of prolonged stress on the immune system?

Inhibition of the immune system leading to increased susceptibility to disease.

Which brain structures are primarily involved in the stress response?

Prefrontal cortex, amygdala, hippocampus, locus coeruleus, and PVN.

What is the effect of chronic stress on the hippocampus?

Reduced dendritic complexity and volume, impairing memory.

What behavioral sign is common in individuals under stress according to Meaney's research?

Less behavioral signs of stress in offspring of high-grooming mothers.

What is the lifetime prevalence of Posttraumatic Stress Disorder (PTSD) in North America?

8.7%.

What are common symptoms of Posttraumatic Stress Disorder?

Intrusive memories, trouble sleeping, irritability, and heightened reactions.

What factors increase susceptibility to PTSD?

Number and duration of traumatic events and genetic differences.

How does PTSD affect the hippocampus?

Individuals with PTSD often have a smaller hippocampal volume.

What changes occur in the amygdala of individuals with PTSD?

Larger volume and increased reactivity to stimuli.

What activity is reduced in the prefrontal cortex in PTSD?

Inhibitory control over stress responses.

What are common treatments for PTSD?

Cognitive behavioral therapy, group therapy, and antidepressants.

How prevalent are anxiety disorders in the general population?

Nearly 30%, more common in women.

What are some types of anxiety disorders?

Panic disorder, agoraphobia, and social anxiety disorder.

What brain changes are associated with anxiety disorders?

Increased activation of the amygdala and decreased activity in the prefrontal cortex.

What is a first-line treatment for anxiety disorders?

Benzodiazepines and SSRIs.

What characterizes Obsessive-Compulsive Disorder (OCD)?

Intrusive unwanted thoughts (obsessions) and uncontrollable behaviors (compulsions).

What brain structures are associated with OCD?

Basal ganglia and frontal lobes.

What serotonergic agent is used in treating OCD?

Fluoxetine.

How can exercise benefit stress response?

Reduces ACTH and corticosterone responses to stress.

What is a key historical finding in psychoneuroimmunology?

The brain regulates immune function and stress affects disease susceptibility.

What example of chronic stress was illustrated with wound healing rates?

Caregivers experienced suppression of wound healing.

How does prenatal stress affect offspring?

Increased response to stress in adult rats if their mother was stressed.

What protective effect does high grooming behavior in mothers have on rat pups?

Reduces stress responses and glucocorticoid release.

What is the effect of early life stress on the dorsomedial prefrontal cortex?

Reduced volume in adults who experienced emotional maltreatment.

How does the complexity of stress responses differ between physical and psychological stressors?

Physical stressors elicit immediate, reflexive responses while psychological stressors engage more complex neural pathways.

What is the relationship between stress and memory formation as indicated by hippocampal health?

Stress can impair memory formation due to changes in hippocampal structure.

What role does the locus coeruleus play in stress response?

Involved in regulating autonomic and endocrine responses during stress.

What common physical health impact results from chronic stress?

Increased blood pressure and immune suppression.

What did the research find about the effects of stress on neuronal plasticity?

Stress can affect synaptic plasticity and neuronal resilience.

What do glucocorticoids do in relation to energy metabolism?

Increase energy availability during stress.

During which developmental phase is stress most impactful on brain development?

Early exposure to stress has long-lasting effects.

Which hormone is primarily involved in the stress response through the HPA axis?

Cortisol.

What role does the amygdala play in emotional responses during stress?

Crucial for fear and anxiety responses, especially during stress.

How does GABA influence the amygdala's activity?

GABA acts as an inhibitory neurotransmitter, reducing amygdala reactivity.

What memory-related function does the hippocampus serve?

Forming episodic memories and contextualizing stressful events.

How does stress impact glucocorticoid receptors in the hippocampus?

Increased number of glucocorticoid receptors can lead to more inhibitory feedback.

What type of physical test indicates heightened sensitivity due to stress?

Increased errors in spatial tasks in stressed rats.

What hormone correlates with cold susceptibility in relation to stress?

Immunoglobulins (IgA) decrease due to stress.

What are some examples of stressors mentioned in the lecture?

Violence, car accidents, and unpredictable life events.