Exam #4 Flashcards
Heath Consequences/Addiction
Chronic stress linked to?
Chronic Stress linked to poor health (morbidity) and higher risk of dying (mortality)
Allostatic load?
- Stress places “wear and tear” on the body.
- Alters immune functioning. Increased inflammation.
Reduced parasympathetic functioning?
slow stress recovery + prolonged inflammatory response + reduce ability to repair physical injury
Telomeres are? Telomere Shortening evidence of?
- Telomeres are caps at the end of chromosomes
- Telomeres get shorter each time a cell divides
- Evidence of rapid aging at the cellular level
Depression, anxiety, and chronic inflammation linked to?
Depression, anxiety, and chronic inflammation linked to more rapid telomere shortening.
* Cells are getting older at a faster rate.
* Thus, the internal organs are too.
Metabolic diseases?
1) Chronic stress is associated with a wide range of “metabolic diseases”
2) Cardiovascular Disease (CVD):
* High blood pressure
* Clogged/hardened blood vessels
* Weakened or oversized heart muscle
3) Type-2 Diabetes:
* Dysregulation of body’s energy needs
* Body becomes resistant to insulin
* Results in too much sugar in the blood
4) Polycystic Ovarian Syndrome (PCOS)
* Common cause of female infertility
* Endocrine dysfunction (Affects reproductive, cardiovascular, digestive, and renal systems).
Unhealthy microbiome?
- Populations of bacteria and other microbes living in (and on) your body
- Plays important role in maintaining health and immune functioning.
Eubiosis (healthy microbiome) vs. Dysbiosis (unhealthy)
1) Eubiosis:
* Mutually beneficial relationship between microbiome and host
* More “good” microbes than “bad” ones
* Reduced inflammation. Better immune functioning.
2) Dysbiosis:
* Unbalanced relationship between microbiome and host
* Can be caused by stress
* Too many “bad” microbes. May lead to disease state.
* Gastrointestinal disease (i.e. Irritable Bowel Syndrome) linked to dysbiosis
* Fecal Transplants as a medical treatment
* Restores the microbiome by transplanting fecal matter from a healthy donor
Stress increases desire for?
1) Stress increases desire for high energy foods (fats and sugars):
* Cortisol regulates the body’s energy stores
* Releases stored energy to respond to stressors
* And… increases motivation to replace energy stores
Dysregulated stress is a risk factor for? Vulnerable to?
1) Dysregulated stress is also a risk factor for poor health behaviors:
* Vulnerable to developing addictions
* Addictions to drugs, alcohol, or other indulgences
* Many forms of unhealthy addictions (i.e. high fat foods, sexual promiscuity, etc)
Interaction of HPA axis with reward motivation?
- Behaviors linked to stress is also driven by reward systems
- Release of ACTH also causes release of beta-endorphin
- A “fearful” response can also be a “rewarding” one
- Can’t assume that cortisol reactivity is consistently linked to aversive feelings
- Risky behaviors can be both frightening and pleasurable (i.e. sky diving)
- Stress increases release of endogenous opioids
- Cortisol increase may co-occur with dopamine release
- (HPA) axis is a system in the body that regulates the stress response and the release of cortisol
Kabbaj et al (2000) “Light-Dark Box”
1) Kabbaj et al (2000):
* Rat model of “sensation seeking”
* Study of rats’ exploration of a novel environment
2) Light-Dark Box paradigm:
* By default, rats prefer a dark environment
* For a rat it’s safer in the dark
* “Light-Dark” box has two sides:
a) One is dark and enclosed
b) The other is open and exposed to light
3) When placed in a light-dark box, rats first move to the dark side
4) BUT…. Eventually… they will want to explore the other side
Two patterns of behavior: High-responding vs Low-responding rats
1) High-responding rats (HR):
* Faster to explore the light side
2) Low-responding rats (LR):
* Slower to explore the light
3) Corticosterone release:
a) HR rats show more corticosterone (cortisol) reactivity
b) LR rats show less corticosterone reactivity
4) BUT… HR rats also show bigger dopamine release in response to the stressor (The novel environment is the stressor)
a) Dopamine involved in reward and reinforcement
5) The HR rats may possibly find the increased risk and stress more “rewarding” (Or at least more “worth it”)
6) But… HR rats were also faster to get addicted to cocaine:
a) In these studies, the rats could self-administer cocaine
b) Press a button get some cocaine infused into the brain
c) HR rats used more cocaine from the start and became addicted more quickly
The Dark Side of Addiction: Brain areas involved in anticipation, intoxication, and withdrawal?
1) Preoccupation/Anticipation:
* Prefrontal cortex
* Thinking about the drug
2) Binge/Intoxication:
* Basal ganglia (striatum) - Coordinates motor movements
* Behavior to use the drug
3) Withdrawal/Negative affect:
* Extended amygdala
* Withdrawal is a stress response
* Attempts to reduce stress by seeking more drug
* Amygdala learns drug use connects with stress relief
Mesolimbic dopamine pathways? Connections and function?
- Connections from ventral tegmental area (VTA) to Nucleus Accumbens (NAc)
- Involved in reward and motivation
- Overstimulation can lead to addictive cravings
Mesocortical dopamine pathways? Connections? Function?
- Connections from VTA to Prefrontal Cortex (PFC)
- Involved in working memory and decision making
- VTA to DLPFCa —> executive functioning (thinking aspects)
- VTA to VMPFC —> emotion regulation (more with cravings)
- Hypo-activity may be linked to poor control of attention, memory, and emotions.
Nigrostriatal? Connections? Function?
- Substantia nigra to the basal ganglia.
- Involved in planning motor movements.
- Impairments leads to tremors, spasms, jerky movement. (Parkinson’s Disease).
Liking vs. Wanting? Brain areas? Activated by?
1) Wanting:
* Mesolimbic and Mesocortical Dopamine pathways
* Activated by dopamine
2) Liking:
- Network of “hedonic hotspots” found in…
- Prefrontal cortex
- Nucleus accumbens
- Ventral Palladium
- Not activated by dopamine
- Activated by endogenous opioids and cannabinoids
brain areas?
Two different aspects of the Reward System: Wanting vs Liking System? Incentive salience?
1) Wanting system:
* Increases incentive salience
* Strong motivations to seek the reward
* Not pleasure from the reward
* Overstimulation from drugs “sensitizes” wanting pathways
* Extended amygdala “remembers” the drug
* Wanting for the drug increases with repeated use
2) Liking system:
* Related to feelings of pleasure
* Activated by opioid and cannabinoid receptors
* Overstimulation causes habituation
* Liking for the drug decreases with repeated use
types and function
Stimulants vs Depressants
1) Physically addictive drugs alter dopamine activity:
* Both stimulants and depressants
* Increase dopamine in the VTA and Nucleus Accumbens
2) Stimulants:
* Nicotine, Cocaine
* Directly stimulate dopamine in VTA (Ventral techmental area) and Nucleus Accumbens
3) Depressants:
* Alcohol, Opiates
* Inhibit GABA neurons (inhibit the inhibitors)
* Results is increased dopamine in the VTA and Nuc. Accumb
What are they? Function?
Cannabis (and endocannabinoids)?
- Specific receptors (at least two types)
- Receptors in hypothalamus, basal ganglia, amygdala, hippocampus, and cortex
- Primarily has inhibitory effects (slows signaling) and pain relieving effect (analgesia)
- Inhibits long-term potentiation (impaired memory)
- Does not lead to physical addiction (May still be psychologically addictive)
- Less activation of CRF system in withdrawal
- CBD (Cannabidiol) may help downregulate HPA axis
- Make people more vulnerable to developing schizophrenia related to genetic differences
post and pre-synaptic neurons
Endogenous Cannabinoids (ECBs)function?
- May function as an innate anti-depressant
- Can reduce anxiety and elevate moods
- Can reduce inflammation
1) Endocannabinoids released from post-synaptic neurons to reduce activity of pre-synaptic neurons
* Neuron to neuron negative feedback system
2) By releasing ECBs, the post-synaptic neuron reduces how excitable the pre- synaptic neuron can be
* ECBs bind the the CB1 receptors on the pre-synaptic neuron
* Reduces activity of excitatory neurotransmitters like glutamate
3) It’s like the post-synaptic neuron looks back and tells the pre-synaptic neuron to “chill out”
Endogenous Cannabinoids (ECBs): CB1 vs CB2 receptors (where is found)
1) CB1 receptors – found throughout the brain:
* Cortex, hypothalamus, amygdala, hippocampus, basal ganglia
* Activation of CB1 receptors inhibits neural activity
2) CB2 receptor – mostly found in the body:
* Reduces inflammatory responses
* May help limit physical injuries
* Endocannabinoids from muscle activity part of the “runner’s high”
Genetic vulnerability for links between schizophrenia and cannabis use
1) Genetic risk of developing schizophrenia increased by cannabis use:
- Due to variations in genes for COMT (catechol-O-methyltransferase)
- COMT enzyme breaks down monoamine neurotransmitters:
a) Breaks down serotonin, norepinephrine, and dopamine - COMT is more active in the frontal lobes:
a) Important for decreasing dopamine activity in frontal lobes
b) Dopamine activity linked to addiction, aggression, and psychosis (schizophrenia)
Helplessness
Voodoo deaths? Walter Cannon.
- Became fascinated with reports of “voodoo deaths”.
- People suddenly dying after being cursed by forms of black magic.
- Those that died believed in the magic.
- Believed there was no escape and the death was inevitable.
- Cannon proposed that fear and emotional strain caused an intense activation stress system.
Engel (1971) newspaper reports of sudden deaths
1) Most cases sudden deaths occurred after an extremely emotional event:
* Death or loss of loved one
* Violent or hostile confrontation
2) Powerful negative emotions, plus feelings of helplessness or hopelessness
3) Most common causes of death:
* Heart attack (myocardial infarction)
* Stroke (blood clots, typically in the brain)
Meta-Analysis of sudden deaths: Heart attacks and strokes more likely after….
- After an episode of intense anger
- During events of widespread threat
a) Earthquakes
b) Bombings - While in a stressful location
a) More likely to die while visiting New York - Uncontrollable or unpredictable events that make feel helpless or hopeless
- Sudden deaths typically occur in people that have pre-existing heart disease
- But, the intense fear, anger, or sadness may stress the cardiovascular system…well… to death
The “Executive Monkey” Study Methods/Design
- The two monkeys experience the same physical stress - Electric shock
- One monkey can “control” whether the shock occurs - The “Executive Monkey”
- Does the psychological difference of having control influence the health outcomes?
a) Which monkey will show more physical signs of stress
b) Gastric Ulcers? - Sideman avoidance paradigm
- Subject 1: “Executive Monkey”
a) Can avoid shock by pressing the lever every 20 sec.
b) (is stressful because must pay attention) - Subject 2: Yoked control
a) Receives the same amount of shock as partner but its lever does not control the shock - Did this for 6 hours on, 6 hours off everyday
design flow
Executive Monkey: Conclusion and Caveats
1) Results
* The “executive monkey” showed more physical stress
* More and larger ulcers
2) Conclusion
* The stress of decision-making lead to the ulcers
* Lead to a stereotype that stressed out businessmen would develop ulcers, BUT…
3) Major Design flaw
* The groups weren’t randomly assigned
* The “executive monkeys” were selected because they learned to press the bar quicker
* The “executive monkeys” were already more reactive to stress
4) Study not replicated
Why “learned helplessness” isn’t really about “learning”: Methods and evidence
1) The “learned helplessness” of rats from the cold water stressor could be eliminated by…
* Repeated exposure to the same stressor. (Rat were able to adapt)
* Giving rats time to recover
* Giving drugs that prevent the breakdown of norepinephrine
and other monoamine neurotransmitters
2) Evidence that “learned” helplessness was being caused by something different than learning
Social buffering in guinea pigs?
- Guinea pigs cortisol response to stressor (Being moved to a new cage)
- Decreased stress response when moved to a new cage with a bonded partner
Social buffering by gender interactions
- Cortisol response to Trier Social Stress Test (TSST)
- Alone, with stranger, with partner
- Overall gender difference in reactivity: Males showed more overall reactivity
- Males showed less reactivity with their partner present (in comparison to being alone or with a stranger).
- Females showed more reactivity with their partner present (in comparison):
a) Assuming heterosexual partners…
b) Boyfriends may cause more stress
c) Girlfriends may reduce stress
Benefits of Forgiveness
1) Benefits of Forgiveness:
* Cardiovascular responses
* Recall being hurt or offended
* Focus of feelings of hurt, holding a grudge, empathy, or forgiveness
2) Hurt Feelings and Holding Grudge:
* Increased cardiovascular reactivity and slower recovery
3) Empathy and Forgiveness:
* Decreased cardiovascular reactivity and faster recovery
