Exam 1 (CHAPTERS 1-4) 4 Flashcards
Fear is what?
Adaptive and necessary to avoid harm
What receives sensory info regarding threat and initiates fear response?
Amygdala
What tells the hypothalamus to trigger hormones?
Amygdala
What tells pons and medulla to control movement, facial expression, and heart/respiration rate?
Amygdala
What integrates emotional content from stimuli to guide response to fear?
Prefrontal cortex
What is used for planning and hurts planning if damaged?
Prefrontal cortex
What is anxiety?
The perception of threat - typically vague
- NOT danger, necessarily, but perceived danger
- Body reacts same way to fear and anxiety
- Anxiety effects can be long lasting because not a specific fear stimulus
Types of Anxiety disorders
1) Panic Disorder with/without Agoraphobia
2) Generalized Anxiety Disorder
3) Post-traumatic Stress Disorder (PTSD) - separate category in DSM 5
Panic Disorder
1) Repeated and unexpected panic symptoms characterized by discrete periods of intense fear
2) At least one month of persistent worry about having panic episode
3) Symptoms may be expected (cued) or unexpected (uncued)
4) with or without agoraphobia
What is agoraphobia?
Fear of panic attack in inescapable situation
Generalized Anxiety Disorder lifetime prevalence?
5%
What is GAD
Excessive worry and difficulty controlling the worry
Pathology of GAD
- Low heritability and NO identified genes
- Strong associations with major depression
- Neurotransmitter of interest: GABA
With GAD, what does it have a deficiency of in its neurotransmitter of interest?
Deficiency in receptor expression and in messenger RBA (transcribes receptor)
What is the lifetime prevalence of PTSD?
8%
What are the 3 primary symptom clusters of PTSD?
- re-experiencing
- avoidance
- hyperarousal
What is the Pathology of PTSD?
- Decreases in hippocampal and pre-frontal cortex volumes
- This is due to increased glucocorticoid and
catecholamine release in response to stress and
underactive prefrontal cortex
- This is due to increased glucocorticoid and
- Enhanced amygdala response
- Not suppressed from cortical inhibition
Who discovered barbiturates?
Bayer laboratories in 1903
What do Barbiturates depress?
CNS
What is a GABA agonist and has effects similar to alcohol?
Barbiturates
What is the problem with Barbiturates?
You can’t separate anxiolytic effects from sedative effects
What kind of therapeutic index do Barbiturates have?
Narrow, especially when combined with alcohol
What has Barbiturates been used for?
Seizures, anxiety, insomnia, and anesthesia
Sodium amytal
Barbiturate used for hypnosis and truth serum (not supported by research due to false memories)
Mechanisms of Barbiturates
- Bind to barbiturate site on ionotropic GABA-A receptor and open a Chloride channel
- Produces hyperpolarization of postsynaptic membrane
- Postsynaptic cells cannot easily produce an action potential which reduces the firing rate in receiving neurons
- Barbiturates can work in absence of NT GABA on barbiturates site in GABA receptor complex
- Net effect: inhibition
Side effects of Barbiturates
- Confusion, impaired judgment, loss of muscle coordination, impaired speech
- Disruption of sleep cycles &REM deprivation
What happens if Barbiturates disrupts sleep and REM a few nights? A week?
few nights: irritability, poor concentration
1 week: psychotic symptoms
Barbiturate tolerance
Increased liver metabolism and GABA receptor downregulation (but NOT with respiratory suppression)
When were Benzodiazepines discoverd?
the 50s ( Librium then Valium)
Benzos Mechansims
Bind to GABA receptor like barbiturates
- Causes hyperpolarization
- Can’t open chlorine channels on their own, need GABA present
Benzos side effects
- Sedation, cognitive impairments, motor movement impairment, slurred speech
- Disrupts sleep cycles when used long term
- Less risk of respiratory depression but still interacts with alcohol
What Benzo produces euphoria, sedation, and amnesia when combined with alcohol?
Rohypnol
Tolerance with Benzos
Benzo receptor downregulation
Third- Generation Anxiolytics two kinds
Partial GABA agonists and Serotonin agonists
Partial GABA agonists
- minimize sedative side effects
- less binding efficacy than full agonists
- not used in US
Serotonin agonists
- 5HT receptors located in anxiety brain areas
- Not immediate effect like benzos but less side effects
- Buspirone is one
Buspirone
Downregulation/desensitization of autoreceptors leading to increased 5HT production
Alternatives for Anxiety
Valerian
- herb (dating back to Hippocrates)
- not well researched
- one study suggested efficacy in mice
Obsessive part of OCD
Recurrent unwanted thoughts
Compulsions part of OCD
Repetitive behavior
Relationship between obsessive and compulsive
Typically compulsions are to prevent or reduce obsessions
- there is a recognition of unreasonable/excessive nature
When is the onset of OCD?
Early adolescence/adulthood but can occur in kids
What is the rate between men and women in OCD
Equal rates (except for kids, greater in boys than girls)
What is the lifetime prevalence of OCD?
2.5%
OCD Pathology
- Neural dysfunction between orbitofrontal cortex, cingulate gyrus, caudate nucleus, globus pallidus, and thalamus
What is Normal vs OCD pathology?
Normal: DA in caudate nucleus inhibits globus pallidus which inhibits thalamus
OCD: DA inhibition in globus palidus leads to lack of thalamus suppression which leads to increased activity in orbitofrontal cortex
Cingulotomy
Surgically disrupting excitatory input from cingulate gyrus to frontal cortex
Can SSRIs and SNRIs be used for Anxiety?
Yes, but mechanism is unclear
What is the initial efficacy of Serotonin on Anxiety disorders?
50-60%
What happens to blood flow for those with an Anxiety disorder who respond to SSRIs or SNRIs?
Decreases blood flow to thalamus
What happens to DA receptors in caudate nucleus when SSRIs or SNRIs are used for anxiety disorders?
It increases
Write out Fight/ Flight and Rest/Digest increases and decreases
Fight/Flight (synaptic NS)
- HR/BP - both increase
- Digestion - Decreases
- Breathing - Rate increases, depth decreases
- Sweating - Increases
- Immune functioning - Decreases
