4. Stress, anxiety and aggression Flashcards
Stress is:
1. A p____ reaction caused by p____ of a____ or t____ situations
2. Change that causes p____, e____ or p____ s____
3. P____ responses help prepare for ‘f____ or f____’ situations
4. E____ or c____
5. A____ but also h____
- physiological, perception, aversive, threatening
- physical, emotional, psychological strain
- Physiological, fight or flight
- Episodic, continuous
- Adaptive, harmful
Physiology of the stress response - SAM system:
1. Threats require e____ a____ –> need to m____ e____ r____
2. S____-A____-M____ (SAM) system
3. H____ and s____ nervous system stimulate a____ m____ (kidneys) to release the c____ t____ e____ (increases bloody glucose) and n____ (increases blood pressure)
4. N____ also secreted in b____ during stress
- enhanced activity, mobilise energy resources (Glucocorticoids mobilize energy stores by inducing the degradation of proteins to free amino acids in muscle,lipolysisinadipose tissue, andgluconeogenesisin the liver.)
- sympathetic-adrenal-medullary
- hypothalamus, sympathetic, adrenal medulla, catecholamine transmitters epinephrine, norepinephrine
- Norepinephrine, brain
Physiology of the stress response - HPA axis:
1. H____-P____-A____ (HPA) axis
2. P____ n____ of the h____ (PVN) releases the peptide c____-r____ h____ (CRH)
3. CRH stimulates a____ p____ to release a____ h____ (ACTH)
4. ACTH enters general c____ and stimulates a____ c____ to secrete g____ –> increases g____, decreases p____ s____
5. CRH also secreted in b____ during stress in l____ system
- hypothalamic-pituitary-adrenal axis
- Paraventricular nucleus, hypothalamus, corticotropin-releasing hormone
- anterior pituitary, adrenocorticotropic hormone
- circulation, adrenal cortex, glucocorticoids, glucose, pain sensitivity
- brain, limbic
Stress can be n____. C____ exposure to g____ destroys h____ neurons via excessive g____ in s____ –> excessive __ influx and toxicity
neurotoxic, chronic, glucocorticoids, hippocampal, glutamate, synapse, Ca2+
(Hippocampus=involved in learning and memory)
Evidence for stress-induced neurotoxicity:
1. Rat exposed to c____ s____ and p____ for 75 mins
2. B____ g____ increased
3. Evidence for n____
4. Impaired p____-b____ potential in h____
5. Impaired in s____ task that requires h____
- cat smell and presence
- Blood glucocorticoids
- neurotoxicity
- primed-burst, hippocampus (PBP; similar to LTP, synaptic strengthening)
- spatial, hippocampus
PTSD involves long-lasting p____ symptoms after t____ event is o____. PTSD likelihood is increased if the traumatic event involves d____ or v____ from o____ p____. Symptoms include f____, h____ and i____. Often triggered by c____ related to traumatic event. L____, c____ response.
psychological, traumatic, over
danger, violence, other people
flashbacks, hypervigilence, irritability
cues
learned, conditioned
Pavlovian associate learning:
1. N____ stimulus is repeatedly associated with an important s____ event called u____ stimulus
2. N____ stimulus comes a c____ stimulus or c____ which signals u____ stimulus
- neutral, salient, unconditioned
- neutral, conditioned, cue, unconditioned
Learned P____ associations play a role in PTSD. N____ stimulus paired with a s____ stimulus. After P____ learning n____ stimulus becomes a c____ stimulus, often called a c____. C____ induces a c____ fear response.
Pavlovian, neutral, salient
Pavlovian, neutral, conditioned, cue
Cue, conditioned
PTSD and brain changes:
1. Reduced size of h____ in combat veterans and police officers with PTSD
2. Possible risk factor for PTSD… m____ twin study from Vietnam war - smaller h____ in those with PTSD
3. Possible reason for h____ and PTSD –> h____ plays a role in d____ c____. Inability in PTSD from detecting t____ vs s____ contexts - t____ g____
- hippocampus
- monozygotic, hippocampus
- hippocampus, hippocampus, distinguishing contexts, threatening, safe, threat generalisation
Altered activity of the amygdala and medial prefrontal cortex in PTSD:
1. P____ c____ involved in i____ c____ and thought to normally i____ a____, involved in e____ e____
2. PTSD associated with greater a____ and reduced PFC activation than controls to f____ f____
3. PTSD-related changes may indicate e____ e____ r____ and r____ i____ c____
- Prefrontal cortex (PFC), impulse control, inhibit amygdala, emotional expression
- amygdala, fearful face (opposite for happy face)
- excessive emotional response, reduced inhibitory control
PTSD treatments:
1. P____ –> associated with decreased a____ activity and increased p____, h____ activity
2. A____ –> increased h____ v____
- Psychotherapy, amygdala, PFS, hippocampus
- Antidepressants (SSRIs), hippocampal volume
C____ e____ therapy is highly effective for PTSD. Borrows principles from e____ learning. Repeated c____ p____ over weeks in safe therapy context reduces response to c____
Cue exposure, extinction, cue presentation, cue
Anxiety is a____ u____ or n____ over an i____ or a____ ill
apprehensive uneasiness, nervousness, impending, anticipated
Anxiety disorder is a more i____ fear/anxiety i____ for the circumstance
intense, inappropriate
Panic disorder is e____ a____ of a____ anxiety or terror. Symptoms include h____, i____ heart-heart, d____ and fear of l____ c____ and d____. C____ factors play a role as A____, A____ and L____ A____ countries have lower rates than e.g. U____
episodic attacks, acute
hyperventilation, irregular, dizziness, losing control and dying
Cultural, Asian, African, Latin American, USA
Brain changes linked to anxiety disorders:
1. Functional imaging using PET and fMRI show changes in the p____ c____, a____ c____ c____, and a____.
2. Increased a____ activity during panic attack (Pfleiderer et al., 2007) and in response to presentations of faces with a____, d____, and f____ in social anxiety disorder (Phan et al., 2005)
–> Activation correlates with symptoms
3. Adolescents with GAD exhibit increased a____ and decreased p____ c____ activation (Monk et al., 2008)
4. Lack of s____ of a____ activation via p____ c____ (PFC)
–> PFC plays a role in i____ of fear
- prefrontal cortex, anterior cingulate cortex, amygdala
- amygdala, anger, disgust, fear
- amygdala, prefrontal cortex
- suppression, amygdala, prefrontal cortex, inhibition
Treatments for anxiety disorders: GABAergic drugs:
1. B____ reduces anxiety and anxiety-like behaviours in a____
2. Binds to i____ G____ receptor as a____
–> increased __ influx
–> H____
- Benzodiazepines (BDZ), animals
- inhibitory, GABAA, agonist
–> Cl-
–> hyperpolarisation
Treatment for anxiety disorders:
1. BDZ administration reduces a____ activity when looking at e____ f____ (Paulus et al., 2005)
2. Flumazenil (antagonist) d____ action at G____ receptor and produces p____ in panic disorder patients.
–> Treats BDZ overdose, acute alcohol intoxication
3. A____ potential, w____, s____.
4. Better c____ are needed with fewer s____ e____.
- amygdala, emotional faces
- disinhibits, GABAA, panic
- Abuse, withdrawal, sedation
- compounds, side effects
Treating anxiety by increasing neurosteroid synthesis:
1. N____ s____ ‘neurosteroids’ (e.g. allpregnaolone) synthesized in p____ and C____
2. increase activity of G____ receptor.
3. During anxiety attacks, neurosteroid synthesis is s____, resulting in s____ of GABAA receptor function.
4. XBD173 enhances neurosteroid synthesis and r____ p____, in absence of s____ and w____ symptoms
- Neuroactive steroids, periphery, CNS
- GABAA
- suppressed, suppression
- reduces panic, sedation, withdrawal
Treatment for anxiety: compounds that affect the serotonin and glutamate system:
1. The anti-depressant fluvoxamine, a SSRI, r____ p____ a____ (Asnis et al., 2001).
2. Similar findings for D-cycloserine (DCS) an i____ a____ of NMDA receptor (Ressler et al., 2004)
3. Presumed action by facilitating ability of b____ t____ to e____ f____ r____
4. DCS facilitates e____ of c____ f____ in animals (Walker et al. 2002)
- reduces panic attacks
- indirect agonist
- behavioural therapy, extinguish fear responses
- extinction, conditioned fear
Aggression is c____ across m____ s____. Related to s____ s____, such as gaining access to m____ and protecting o____. May involve behaviours related to t____, d____, s____.
common, many species
species survival
mates, offspring
threat (warning), defensive (attack), submission (accept defeat)
The brain circuits of aggression are programmed by the b____ s____. Electrical stimulation of p____ g____ (PAG) elicited aggressive attack and predation in c____.
M____ hypothalamus –> d____ PAG: d____ rage
L____ hypothalamus –> v____ PAG: p____ attack
A____ n____ control these pathways
brain stem
periaqueductal gray, cats
Medial, dorsal, defensive
Lateral, ventral, predatory
Amygdalar nuclei
Aggression and serotonin: animal studies:
1. I____ serotonin t____ reduces aggression (Audero et al., 2013)
2. R____ serotonin transmission via d____ of s____ a____ (Vergnes et al., 1988) or reducing serotonin s____ increases aggression (Mosienko et al. 2012)
3. Low levels of serotonin m____ (5-HIAA) in c____ fluid in rhesus monkeys linked with high levels of aggression (Howell et al., 2007)
–> Picking fights with b____ monkeys
–> High r____ taking (dangerous leaps)
–> Suggests serotonin i____ aggression and c____ risky behaviours
- Increasing, transmission
- reducing, destruction, serotonergic axons, synthesis
- metabolite, cerebrospinal, bigger, risk, inhibits, controls
Aggression and serotonin: human studies:
1. Some evidence that s____ neurons play an i____ role in aggression
2. Low 5-HIAA in CSF linked with aggression and a____ behaviour
3. S____ has shown to reduce aggressive behaviour in some cases
- serotonergic, inhibitory
- antisocial
- SSRI
SSRIs work for P____, a____ d____ and a____
PTSD, anxiety disorders and aggression
Reward is defined as o____, a____, e____ that attains a p____ m____ p____
objects, actions, experiences, positive motivational property
Aggression as a reward:
1. Certain individuals exhibit ‘a____’ aggression, motivated by i____ reward (Elbert et al., 2010)
2. Thought to be an a____ to v____ e____ (Crombach et al., 2013)
–> Remaining more f____ in violent settings (war afflicted communities, e.g. Ugandan Child soldiers)
–> Elevated s____ s____
3. Animal models allow us to study this behaviour (and brain mechanisms) under c____ c____
–> Conditioned p____ p____ (CPP)
–> I____ conditioning
- Appetitive, intrinsic
- adaptation, violent environments, functional, social status
- controlled conditions, place preference, instrumental
Examining aggression reward in animals-1:
Conditioned Place Preference (CPP)
* Typically used with drug, food, social reward in mice/rats.
Before conditioning
*: all chambers are n____ stimuli.
* Conditioning: One chamber is paired with r____ (drug) where as the other one is not.
*After conditioning: After several r____-chamber pairings, r____-paired side acquires m____ s____ and acts as a c____ s____
*If a substance/experience is ‘r____’ then animals will spend m____ t____ in that chamber paired with that substance/experience, i.e. develop a preference.
neutral
reward
reward, reward, motivational significance, conditioned stimulus
regarding, more time
CPP with aggression reward:
R____ vs i____ males
Male rodents are very t____ after sexual experience and will attack the unfamiliar intruder
During conditioning: Resident attacks the intruder in the ‘P____’ side, no intruder on the ‘U____’ side
After conditioning: Resident mouse that exhibited aggression spends more time on the P____ side in the a____ of the intruder mouse.
→aggression is rewarding because the attacker p____ the side ‘p____’ with aggression
resident, intruder
territorial
paired, unpaired
paired, absence
prefers, paired
Operant/instrumental task for aggression reward:
Animals will learn to l____ p____ for ‘i____’ (aggression s___-a____). Trained animals p____ l____ even in a____ (aggression-s____)
lever press, intruder, self-administration
press lever, absence, seeking
Does aggression SA and seeking activate the reward system in the brain?:
The n____ a____ (NAc) plays a key role in r____ (e.g. food) and m____ actions (e.g. eating) together with the v____ t____ a____ (VTA).
*VTA sends d____ projections to NAc and part of ‘m____ pathway/system’
-e.g. Food and drug-seeking
*Activated by r____ experiences, e.g. drugs of abuse, food, water, and sex.
* Measured by the a____-s____ p____ ‘Fos’
nucleus accumbens, reward, motivated, ventral tegmental area
dopamine, mesolimbic
rewarding
activity-sensitive protein
Fos is a protein expressed in activated neurons:
Strong stimulation of n____ triggers the expression of a protein called ‘Fos’ (or c-Fos)
We can detect a____ neurons in the brain using a biochemical assay called ‘i____’
When animals are exposed to stimuli that are r____ (e.g. food, drugs) more neurons are activated in the n____ a____ than normal
neurons
activated, imunohistochemistry
rewarding, nucleus accumbens
