Emotion Flashcards
What is an emotion?
subjective mental state that is usually accompanied by behaviors and physiological changes
What did Darwin think about emotions?
-behaviors that are homologous to emotions are observed in many species
-facial expressions and postures send signals to approach or avoid
(Dog example)
-behaviors evolved and USED FOR COMMUNICATION
Paul Ekman
A psychologist who went around the world and studied people of different cultures and their facial expressions
Ekman’s results
- there was a lot of agreement on what happy looked like
- the more isolated the cultures he studied were, the less agreement they had about the basic facial expressions
- this suggests there could be a biological component to emotion
What happens in the fear conditioning mice experiment?
They take a mouse from their “home” and put it in a new place. Then they make this sound and they will get the sound immediately before getting a shock. This happens a couple times and then the mouse goes home.
What are the two ways in which you can tell the mouse learned something from fear conditioning
Context conditioning and que conditioning
context conditioning
return the mouse to where fear conditioning occurred and you’ll see an increase in blood pressure and corticosterone
- and you’ll see and increase in freezing behavior
(don’t need the sound)
Que conditioning
- This happens in the home cage
- play tone in home cage and you will get an increase in BP, corticosterone, and freezing behavior
Amygdala is more important for…
short term responses
- still needed for fear memory
Hippocampus is more important for…
long term responses
What does the medial central nucleus (amygdala) control?
physiological responses to threats
What is the lateral central nucleus (amygdala) important for?
more important for fear learning, probably through connections to hippocampus
Activity is altered when an ion channel is exposed to…
a specific wave length of light
-can be either inhibitory (halorhodopsin) or excitatory (channelrhodopsin)
If you are activating a channelrhodopsin you are…
depolarizing the cell
If you are activating a halorhodopsin you are…
hyperpolarizing the cell, making it harder to for them to fire neurons
Optogenetics
most common use of viral vectors is to induce expression of light-sensitive ion channels into neurons
What are the light-sensitive channels in optogenetics?
They allow the activity of the neuron to be controlled with a fiber-optic cable
What is channelrodpsin?
A genetically modified ion channel that becomes activated by blue lights
- when it is activated it allows sodium inflow (depolarization of the neuron) which makes it more active
Channelrodopsin allows you to…
control the activity of the neuron
What happens when you put blue light into the CEM?
neurons with ChR are depolarized
- freezing behavior increases when blue light is on
What is the control in the CEM with light experiment?
Mice who get the blue light but don’t have ChR so they don’t freeze
Why do you have to use virus in the CEM w/ light experiment?
In order to express ChR in CEM
What does a GABA agonist do to the neural activity?
It inhibits neural activity
What happens when muscimol is infused into CEL ?
It did NOT reduce freezing behaviors when measured before shock exposure
In temporary inactivation what do we us muscimol for?
We use it to inactivate the CEL BEFORE conditioning and then we do the cue exposer a day later
What is the temporary Inactivation experiment studying?
Whether you need the CEL to learn a fear memory and to detect a que
CEL doesn’t promote _______ on its own
freezing
CEL is necessary for __________
forming a fear memory
What is muscimol?
It is a GABA agonist and we use it to inactivate different parts of the brain
What is the difference between CEM
CEM- more important for the fear freezing response and less important for remembering
CEL- more important for learning less important for fear freezing
What does methylation do to DNA?
It decreases its expression
Where does DNA methylation occur?
In the hippocampus which contributes to the fear memory
What are they doing in the DNMT experiment
They do the fear conditioning experiment, and then one group gets injected with DNMT right after and another group gets injected 6 hours later
What were the results of the DNMT experiment?
The mice that got to injection right away didn’t have freezing behaviors and the ones that got injected later did
What part of the brain is used for forgetting a memory?
frontal cortex
What does a frontal cortex lesion do?
It kills off neurons by over exciting them
What happens in the extinction
The mice get the tone without the shock
- eventually they forget because they aren’t getting the shock
What is the conclusion for the extinction experiment?
Lesions in the frontal cortex make it harder to unlearn a fear memory
