Emotional Brain- Rage, anger, aggression Flashcards
(30 cards)
What are the basic 4 systems?
SEEKING system: pleasure, reward
RAGE system: anger
FEAR system: anxiety
PANIC system: separation, distress
What are the 3 types of rage?
- Intrasexual aggression (typically male- male aggression) - in any of sexes
- Fear-induced or aversion-induced aggression - when you’re cornered, flight/fight
- Irritable aggression or frustration- induced aggression- get rat to push button for food, food stops one day, get displacement aggression cause so frustrated
Difference between aggression and aggressiveness?
• Aggression = act, action or behaviour • Aggressiveness = (pre-)disposition,
trait, tendency, likelihood, probability
In other words, aggressiveness increases the likelihood of aggression.
What are higher areas dependent on? What does this suggest?
- Higher areas (amygdala) are dependent on lower areas (PAG).
- This suggests that the amygdala plays a modulatory role.
- Complex, or social perceptions and motivations leading to frustration, etc.: AMYGDALA
- Simple perceptions and motivations (hunger, sex): PAG
How do we know that androgens control sex and aggressiveness?
- Gender data: Males vs. females
- Developmental data: Puberty (aggression rises even in girls)
- Seasonal data: Breeding seasons (seasonal breeders become more agg.)
- Experimental data: Castration studies (if castrate too late in life may have no effect whatsoever
How did biting after gonadectomy compare in female and male mice? After testosterone therapy?
Decrease in male, no change in female (stayed low)
-castrated males increased biting with hormone therapy
What is testosterone in men related with?
Antisocial behav, hostility, non-aggression correlated with family happiness and low T.
What is testosterone in women related with?
Unprovoked violence
Which animals show no effect of castration?
Red sided garter snakes, euro stalings, mongoloian gerbils, wood rats
syrian hamsters show now effect of biorhythms
What are the two main potential changes in rodents?
Androgen concentrations Receptor sensitivity (seasonal)
Why might not replacement treatments in rodents have effects?
Because of the androgen receptors in the brain not responding to the replacement.
What will happen to receptor tissues if not exposed to androgens, and what would this explain?
The tissues will desensitize and this may explain seasonal changes
-could apply to humans(loss of sex interest) and changes in metabolizing enzymes as well
What works as a treatment for criminals/sexual offenders with excessive libido?
Both irreversible castrationa nd reversible, cyproterone acetate competes with T for receptor sites
In sports/aggressive encounters, what will happen if there are too many defeats outside the home cage?
Will lead to defeats in home cage even if intruder is smaller
Why does the home cage advantage disappear?
- Stress response via “fear” conditioning • Persistent response: 33 days • Increase in HPA axis activity*:
- Increase in ACTH, beta-endorphins, corticosteroids
- Decrease in T and PRL • Suppression of the immune system**
Correlation between 5-HT and aggression? How to measure?
- Negative correlation between 5-HT and aggression.
- Main measure: The 5-HT metabolite 5- HIAA (5-hydroxyindoleacetic acid) from the CSF.
- Mice with 5-HT receptor genes knocked-out are hyper-aggressive.
What are individuals with low 5-HT like?
- Violent individuals with alcohol use (Virkkunen and Linnoila, 1993)
- US marines expelled for excessive violence (Brown et al, 1979)
- Children that torture animals (Kruesi, 1979)
- Children with disruptive behaviour • People that commit suicide
What is serenics?
Anti-aggressive agents targeting the serotonergic system.
Example of serenics?
Example: Eltoprazine (serotonin receptor agonist). • ≫ 5-HT-1A receptors.
• Decreases aggressive behaviours without sedation. • ≫ Post-synaptic 5-HT receptors.
• Increases friendly and exploratory behaviours. • ≫ Presynaptic inhibition of serotonin cell bodies.
What are aggression promotors? List
Substance P, glutamate(high levels correlated with aggression), Acetylcholine
What happens when ACh agonists are administered in regions of brain in cats where electrical stimulations induce agg behaviour?
ACh agonists increase hissing in cats
Fear or anger?
What is the major issue with glutamate and ACh antagonists as anti-aggressive agents/
They target many other functions so neg side effects are likely
Aggression levels associated with each substance:
NE
Gaba
Substance P
NE= high levels increased aggression (beta-NE receptor blocker reduces aggression- Propanolol)
Gaba= high levels decreased aggression (although some like alcohol may increase it)
Substance P=increase aggression
How do opiates affect aggression?
Opiates promote well being, withdrawal increases aggressive acts in humans and animals
