BioPSC EXAM 3

Describe fear conditioning

A species is trained to associate a tone with an electrical shock, After this training the species will freeze when hearing the tone.

What is a conditioned stimulus?

Something that predicts a unconditioned stimulus

What are 2 types of fear memories?

Context dependent

Cue Dependent

What are the 2 response variables in the Bechara et al study?

Emotional Conditioning (skin conductive response)

Declarative memory (Describing what happened)

What does the Bechara et al study show?

It showed that emotional involuntary learned responses can be disassociated from declarative learning. Plus, different neural pathways may contribute to this

What is a caveat of the Bechara et al study?

Later studies of humans and animals show overlap in the amygdala and hippocampus more the original studies suggested. (no specific brain region just for emotional or declarative memories.)

What is stress?

a state of threatened homeostasis

What does the Hypothalamus produce?

corticotropin-releasing hormone (CRH)

What is Corticotropin releasing hormone?

A chemical sent to the pituitary gland that promotes the release of adrenocorticotropin hormone(ACTH).

How does CRH travel through the body

Through the blood stream

Cortisol in humans and Corticosterone in rats are both ____________.

Glucocorticoids

What are the 3 ways to "turn off" cortisol?

-Inhibit ACTH release from pituitary

-Inhibit CRH release from hypothalamus directly

-Inhibit CRH from hypothalamus INDIRECTLY(Hippocampus)

What mediates negative feedback?

Glucocorticoid receptors.

What NT is being released when your heart rate, breathing, and blood pressure all increase?

Norepinephrine

Epinephrine is released by the ____________.

adrenal medulla

Blood-glucose levels increase when this NT is released?

Epinephrine

Long-term stress is

maladaptive

Short-term stress is

Adaptive

What hormones are in charge of making immediately usable energy?

Stress hormones

Acute activation of Glucocorticoids (Short-term high stress). Takes energy from where?

Takes sugar from the liver.

What does acute activation of SNS cause?

It inhibits digestion

With chronic activation of the SNS what can it cause?

Reduces energy intake and leads of ulcers.

What is allostatic load?

wear and tear on the body caused by prolonged or excessive stress responses

What are the four types of allostatic load?

1) Repeated "Hits"

2) Lack of adaptation

3) Prolonged response

4) Inadequate response

What must be reduced for tissue formation and remodeling to proceed?

Inflamation

What is the general concept of Optogenetics?

When an ion channel is exposed to a specific wavelength of light, activity is altered.

When a ion channel is exposed to a INHIBITORY wavelength; what is it called?

Halorhodopsin

What does light do to the ion channel?

Changes the shape.

When blue light is administered to CeM, What happens?

The neurons expressing ChR are depolarized (become more active) This induces "freezing"

Inactivation of the hippocampus disrupts what process, without disrupting the response themselves

Disrupts the formation of fear memories.

What is Muscimol?

Its a GABA receptor agonist, which means it inhibits neural activity.

What does DNMT inhibitors reduce?

DNA Methylation

What is the use of a DNMT inhibitor?

They are used to test whether methylation is an important biological process.

Does low freezing occur when DNMT is injected immediately after learning?

Yes, early DNMT injection produces impaired memory. formation

Does High freezing occur when DNMT injection is delayed after learning?

Yes, DNMT injection must be immediate to manipulate memories.

What is observed in human patients diagnosed with PTSD?

Less activity in prefrontal cortex

What is the evidence that TMS can treat PTSD?

TMS can effectively reduce PTSD symptoms, particularly when targeting the right Dorsolateral prefrontal cortex (based on meta analysis)

What are the effects glucocorticoids have on severely ill Covid-19 patients?

Systemic steroid use (Glucocorticoids) in severely ill covid patients will cause less deaths. 87/1000 will live. This is because glucocorticoids suppress the bodies overwhelming inflammatory/immune response.

How is depression associated with cortical rhythms?

this is not all patients, but some will experience high cortisol at night due to an absence in cortical rhythm. increasing allostatic load.

(ON EXAM)What are some explanations for smaller hippocampal sizes in the depressed?

(Remember ALL OF THE ABOVE <3)

Depression could be the culprit. (not leaving the house and creating new synapses)

If you had a small hippocampus from the start, depression is more likely.

Is depression associated with cell death?

No, there is very little evidence, its still inconclusive.

A persons ability to adapt to acute stress, trauma, or chronic forms or adversity is called what?

Resilience

The glucocorticoid response in resilient individuals have what trait?

The responses are rapid; Think rapid onset, rapid off set

Can we say that stress reduces hippocampus size in mice?

No! Because the hippocampus did not get smaller.

In the rat stress study. How was control important in reducing cortisol levels in rat 1

Rat one would receive a shock, but could control it by spinning his wheel. whereas Rat 2 had high Cortisol levels because he had no control over the shocks :(

In the rat stress study. How was Predictably important in reducing cortisol levels in rat 1

Rat 1 would be shown a light right before the shock which allows him the better "prepare". Rat 2 got shown nothing, shocks were completely random.

In the rat stress study. How was having an Outlet important in reducing cortisol levels.

When restrained, giving a rat something to chew on reduced cortisol levels. (Kinda like how most people chew gum during an exam to "Feel better")

Describe the positive effects of schizophrenia?

Hallucinations

Delusions

Disorganized speech

Describe the negative effects of schizophrenia?

Social withdrawal

Reduced expression of emotions

Reduction in verbal communication

What is the current best combination of tr4ament for schizophrenia?

Lowest possible does of antipsychotic medication

Family/ individual therapy

Swift treatment after first episode.

How does Chlorpromazine work?

It blocks dopamine, serotonin, glutamate, and AcH receptors in the brain

Which drug blocks serotonin and dopamine receptors?

Clozapine

What drug class is Fluoxetine?

SSRI - selective serotonin re-uptake inhibitor

What are the side effects of chlorpromazine?

Motor (tremors)

worsening cognitive symptoms (depression)

Sedation and weight gain.

What is the difference of fluoxetine and Imipramine?

Imipramine blocks the re-uptake of both Serotonin AND Norepinephrine, Norepinephrine blocks just Serotonin

Work in rodents showed that Glutamate receptors MAY affect depression related behaviors. Why?

When depressed mice (the control group) are exposed to an uncontrollable stressor they stop trying to

escape. :(

When a ketamine-like drug is administered, this behavior ceases due to the blocking of glutamate receptors. They are able to keep going an escape! :)

What are 2 mechanisms of action for ketamine?

It inhibits NMDA receptors (Blocks glutamate)

It also activates Mu-opioid receptors

What is the significance of the difference between male and female rats on ketamine.

It means that it will be vital to include males and females in future clinical trials of the drug.

What is the primary ligand for Kappa receptors?

Dynorphin

The first K-Opioid antagonists blocked the receptor for weeks with just one dose. What was the downside which haulted the study?

It caused abnormal heart rates in some patients

How does administration of K-Opioid receptors effect outcome?

Using the K-Opioid antagonist BEFORE stressor prevents changes in behaviors. (It has a protective effect!)

What is a Genome-Wide Association Study?

It uses genetics research to associate specific genetic variations with particular diseases. It looks at diseased individuals(eg. Diagnosed with schizophrenia )and controls and maps out where in their DNA is there major differences.

The different genotypes are associated with

differences in the _______________.

the extent to which this gene is turned on.

What area of the neuron is C4 found?

C4 is located in the dendrite.

What is the difference between C4 expression in rats and humans.

In humans: it posed an increased risk of schizophrenia

In rats: C4 promotes synaptic pruning

What's a weakness of the mouse model?

Didn't look in the hippocampus

Didn't manipulate the level of C4 like in human data

What is an emotion?

a subjective mental state that is usually accompanied by distinctive behaviors as well as involuntary physiological changes

In the Bechara study, an individual with selective damage to the hippocampus was found to ________________.

Show activation of the SNS to the conditioned stimulus but couldn't explain why he had this response.

Describe an accurate description of patterns of cortisol secretion reported for patients with depression

Some patients with depression have elevated cortisol levels 12 hours after a dexamethasone injection.

How did researchers assess frontal cortex activity in patients diagnosed with post-traumatic stress disorder?

The performed a FMRI imaging while patients were exposed to words or images related to trauma.

Today's state of the art treatment for breast cancers uses __________ whereas treatment for depression generally uses ____________.

Mechanisms based Strategies - Trial and error strategies

Which receptor is preferentially activated by cortisol when cortisol levels are low?

MR (Mineralocorticoid receptor)

After fear conditioning training, how could you test whether a mouse has developed context-dependent fear memories?

Return the mouse to the fear conditioning cage without playing the tone used during fear conditioning.

Experiments manipulating the function of the medial central nucleus of theamygdala (CeM) showed that ____________.

Activation of CeM rapidly increased freezing behaviors

Willow the cat has just narrowly escaped being chased by a large dog. One hour later, while safely taking a nap inside her house, her cortisol levels are still elevated.In most other cats, cortisol levels would have returned to baseline by this time. Willow's condition after escaping the dog can be described as a state of__________

Increased Allostatic load

The antidepressant effects of ketamine have a different mechanism from standard antidepressants like selective serotonin re-uptake inhibitors like Prozac. This is because ketamine directly targets ___________

Glutamate (NMDA) receptors

Explain the lists the steps of optogenetic inhibition of a neuron in thecorrect order

1) Viral expression of halorhodopsin.

2) Apply yellow light to the brain.

3) Influx of chloride ions.

4) Hyper-polarization of the neuron.

Facial expressions and postures send a signal to _____________

Approach or Avoid

What did Darwin believe about emotion?

That emotions are behaviors that appear similar to emotional states seen in many species.

What did Darwin predict about human emotion?

He predicted that human emotional states would be consistent across cultures.

Which emotional state was consistent across cultures?

Happiness

Similarities in emotional expression suggest?

That there is a genetic component

Differences in emotional expression suggest?

That there is a environmental component

What is a unconditioned stimulus?

Not Learned- Something that generates and unlearned behavioral response

What is the unconditioned response?

an unlearned reaction to an unconditioned stimulus that occurs without previous conditioning

What is a conditioned response?

Learned response to a conditioned stimulus. (freezing after tone, but no shock)

What is a stressor?

What ever is responsible for the imbalance. (This class, Cost of living, ect.)

What is the stress response?

the body's response to the imbalance. (B.P change, hormones, sweat)

ACTH travels to which area of the body?

The adrenal glands

Mineralocorticoid receptors have a higher affinity for ___________ than glucocorticoids.

Cortisol

When cortisol levels are low, ______________ is preferentially activated.

MR (Mineralocorticoid receptors)

If Glucocorticoid receptors are activated this is a sign of what?

Higher cortisol levels

MR is activated when cortisol is _______, GR is activated when cortisol is ________.

Low, High

Chronic Activation of Glucocorticoids (Long-term high stress). Takes energy from where?

Break down lipids and proteins. (energy reserves)

What is Allostasis?

The bodies response to daily events to maintain homeostasis'

What are Repeated "Hits"?

Living in a stressful environment where you are exposed to a lot of stressors that you need to respond to quickly. Increasing allostatic load.

What is "Lack of adaptation"

Inefficient adaptation of stress response, or response is given in non-threatening situations.

What is a prolonged response?

After the stressor, the physiological response is maintained. So no recovery; Each response costs more energy.

What is the inadequate response?

When the body's systems fail to react appropriately to a stressor, often because they are unable to shut down properly or have a weak response.

When a ion channel is exposed to a EXCITATORY wavelength; what is it called?

Channelrhopsin