Gut-Brain Axis
Identify at least one way that stress can affect the bacteria in the gut.
-Increase constipation
-Slows small intestinal transit time
-Encourages overgrowth of bacteria
-Compromises the intestinal barrier
What is the adaptive hypothesis of sleep?
When animals have adapted how much they need to sleep based on food availability and safety.
Briefly describe the James-Lange Theory of emotion.
An emotion producing stimulus leads to a physiological response. Only then is the emotion felt.
What is the relationship between the serotonin gene, stress, and depression?
A short allele for the 5-HTTLPR serotonin transporter gene causes more vulnerability for depression, in addition to an amygdala that is hyperactive to stress and emotion.
What is anterograde amnesia vs. retrograde amnesia?
Anterograde: cannot form new memories (front/future)
Retrograde: losing memories from the past
Things we eat can affect and even reduce neurotransmitter production. Which neurotransmitter impacts anxiety levels and is affected by what someone eats?
GABA
What are sleep spindles?
Sleep spindles are bursts of brain activity that aid in memory consolidation (occurs in stage 2).
The sympathetic nervous system is to activate and arouse, as the parasympathetic nervous system is to...
Rest and recovery.
How heritable are anxiety disorders?
30-50%
Where are memories stored?
Memories are temporarily stored in the hippocampus and then transferred to cortical areas based on where the information was processed or experienced.
What is the microbiome, and what part of the body is a habitat for it?
The microbiome is all the bacteria in the body. Its habitat is the stomach.
What is the function of adenosine, and how does coffee affect it?
Adenosine makes you tired, breaking down and dispersing as you sleep.
Coffee affects adenosine by suppressing it. Caffeine suppresses adenosine by binding to adenosine receptors and blocking its ability to slow nerve activity.
When someone's in a state of arousal, what is most likely to happen to their eyes, mouth, and heart rate?
Hint: Think of the NS chart!
Eyes: Pupils are dilated, eyes are dry, and far vision is activated
Mouth: Dryness/lack of saliva
Heart Rate: Increased in comparison to its resting state
What is ECT, when is it typically used, and what are the typical resulting neurotransmitter effects?
Electroconvulsive therapy administers 70 to 130 volts to the right hemisphere, causing rapid effects (9x higher improvement). It can increase the sensitivity of serotonin receptors and promote the release of norepinephrine. Additionally, there are increases in dopamine release and GABA levels.
Creating new memories is dependent on which brain areas?
The hippocampus and the amygdala.
Why is gut function suggested to be tied to Autism Spectrum Disorder?
There is 95% comorbidity in ASD and GI disorders. Additionally, probiotics, prebiotics, and gluten free diets have shown success in reducing symptoms of ASD.
How does melanopsin work?
Melanopsin is a photopigment at the ganglion cells that is broken down by light, telling the brain we have seen light (sends signals that it's daytime).
How does the Insula contribute to emotion?
The Insula receives interoceptive feedback, which could be information from organs or the state of the body (e.g., changes in heart rate). It integrates with other areas, leading to the communication of information to other limbic system structures. Additionally, the insula is involved in processing taste and disgust, which explains why many people eat to feel better (taste) and experience pronounced emotional responses (disgust).
What are the brain correlates of depression that were covered in class?
-Decrease in volume, but increase in activity in the PFC
-Increase in volume and activity of the Amygdala.
-Increase in volume of the hypothalamus
-Decrease in volume of the hippocampus
How do declarative and nondeclarative memory differ? Be able to provide examples for each.
Declarative: facts/things you could tell someone about (relies on the hippocampus)
-Remembering the name of a restaurant you went to last night
Nondeclarative: procedural/muscle memory, how something is done (dorsal streams)
-Remembering how to ride a scooter
What is intestinal permeability, and what symptoms correlate with it?
Intestinal permeability occurs when gut lining gets inflamed and large proteins (like undigested food) escape into the blood.
Symptoms include:
-Autoimmune diseases and inflammation that presents as depression, brain fog, skin problems, metabolic problems, allergies, and asthma
Explain why we would expect performance to decrease during 3 straight hours of sustained effort on a task.
According to the basic rest-activity cycle, people’s alertness is based on a 90-120 minute interval, with 20 minutes involving the Ultradian healing response. The body is not designed to maintain full attention for three hours at a time, as the brain operates on a different biological clock.
Explain how facial feedback, mirror neurons, and the experience of empathy are proposed to be related.
Facial feedback refers to afferent information sent to the brain, indicating that a person’s facial expressions can influence their emotional state or experience. Empathy is sharing the feelings of somebody else (experiencing someone else’s emotions as your own). A mirror neuron is a neuron that is active when you do something and when you perceive someone else doing something (e.g., causing you to potentially match the facial expressions of someone you’re having a deep conversation with). This may play a role in empathy, as the facial feedback hypothesis suggests that mirrored facial expressions can influence you to feel what another person is feeling.
Be able to identify and explain how the brain networks each contribute to anxiety (e.g., orienting, default network, etc.).
The ventral attention network (vIPFC) is involved in orienting attention and detecting things that could be harmful, meaningful, or amiss (quickly grabs attention — “What is that?”). Salience is related to error detection, characterized by exaggerated responses to incorrect predictions (ACC), which involves recognizing when something is wrong. Executive control (dIPFC, parietal) is the hyperactive worry and problem-solving system. Lastly, the default network (mPFC) controls self-monitoring and awareness.
Explain what in HM’s brain was removed during surgery and what effects he experienced afterwards (which functions were preserved and which were lost).
Patient HM’s medial temporal lobes were removed, destroying his hippocampus and mostly removing his amygdala. The amygdala damage resulted in HM experiencing mostly positive emotions. In terms of memory, HM experienced anterograde amnesia, accompanied by some retrograde amnesia of newer memories. He lost declarative memory, which relies on the hippocampus, causing HM to struggle with the “What” (facts/things he could tell you about). However, he preserved functions related to nondeclarative (procedural/muscle) memory, being able to remember the "How."