Learned Helplessness

What is active avoidance behavior?

Animals learn that a behavior performed during the CS prevents the US from benign delivered

What is Two Factor Theory?

1. 1st factor

   1. Learned fear acquired through pavlovian processes

2. 2nd factor

   1. Instrumental behavior that occurs when a response causes fear reduction

What did a series of studies show when a restrained animal is given too many tone shock pairing?

It will never acquire avoidance even when it is free to do so

What is learned helplessness?

The acquired belief that “ nothing one does matters”

What is a result of learned helplessness?

Opportunities to maximize benefit or minimize harm will be ignored

What is objective helplessness?

When the probability of an important outcome is just as likely in the presence and absence of an action

What is an example of objective helplessness?

If a rat is just as likely to get a food pellet in both the presence and absence of an instrumental behavior like a lever press

What is subjective helplessness?

The expectation that outcomes encountered in the future will occur independently of your actions

What is it called when subjects are paired so that one, the master, controls what happens to both itself and its partner, the yoke?

Yoked control design

Describe the yoked control design.

1. Master yoke pairs of subjects exposed to tail shocks that the master can inactivate with a wheel turn

2. All subjects later received CS-US (tone shock) pairings in a standard fear conditioning paradigm

A light ___ predicts a mild shock to the tail ___.

1. CS

2. US

What is an example of avoidance response?

If the subject touches a button with its nose during the tone, the US is omitted

In the experiments, examining control & the effects of stress, describe the yoked control design.

1. Subjects are paired so that one, the master, controls what happens to both itself and its partner, the yoke

2. The third subject gets no shock

What were the results to the control and effects of stress yoke control design?

the yokes lost weight and developed gastric lesions (ulcers)

How did Baratta inactivate MPFC?

1. With muscimol at various experimental time point 

What did mPFC inactivation during master-yoke tail shock, followed by fear conditioning result in?

1. What did master-yoke tail shock, followed by mPFC inactivation during fear conditioning look like?

What is the name of the structure with major serotonin-producing nucleus in the brain stem?

1. ____ counts in DRN neurons that produce________.

1. C-Fos

2. Serotonin

What is the name of the protein that is expressed when cells undergo synaptic engagement?

1. c-Fos

1. What implements the effects of control and how does it do it?

1. mPFC

2. inhibits serotonin neurons

What can stressors (like shock) activate in the DRN?

Serotonin neurons

What happens to the mPFC during controllable stress?

activated to decrease the activity of these neurons via feedforward inhibition

What does serotonin release in the amygdala do?

1. Increases activity in that structure

1. What does inactivation of the DRN serotonin cells lead to?

 A less active amygdala when shock is controllable

1. Where do the mPFC project to?

1. The dorsal raphe nucleus (DRN)

1. Once the mPFC contacts inhibitory GABA neurons in the DRN, … ?

1. They contact DRN serotonin (5-HT) neurons

1. Where do the DRN serotonin neurons project to?

1. Throughout the brain, including the amygdala

1. What is a major treatment for depression?

Selective serotonin reuptake inhibitors (SSRIs)

1. What do SSRIs do?

They are drugs that prevent the removal of serotonin from the synapse which leads to a broad increase in serotonin concentrations

1. Where does serotonin project to?

projects widely throughout the brain, and its effects differ from place to place

1. The mood altering effects of SSRI’s may be ________ from serotonin itself.

1. Downstream

1. Though serotonin levels increase quickly on SSRIs, therapeutic effects can take _________?

Weeks

Where does the mPFC project to detect behavioral control?

1. mPFC projects to dorsal medial striatum (DMS)

1. What is the DMS?

1. A region crucial for the initiation of voluntary motion

1. The DMS is highly implicated in which disease?

1. Parkinson’s disease

1. What are the major symptoms of parkinson’s

1. Akinesia

2. Bradykinesia

3. Resting tremor

1. What is akinesia

1. Difficulty initiating motion

1. What is bradykinesia

1. Slowness of motion

1. What does the DMS also play a key role in?

1. Detecting the relationship between voluntary actions and the outcomes they cause

1. Describe the neural circuit model of learned helplessness.

1. mPFC-DMS projections detect control (or helplessness)

   1. Important for objective helplessness

2. mPFC-DRN projections implement the expectation of control (or helplessness)

   1. Important for subjective helplessness

1. Though helplessness was the initial focus, it is possible that control is what’s _______, the __________state may be the default, which control inoculates against stress.

1. Learned

2. Helpless

1. __________ is a combination of objective helplessness or a lack of influence over one’s environment, and subjective helplessness, or the expectation that nothing one does will matter in the future.

1. Learned helplessness

1. What do mPFC projects to the dorsal striatum play an important role in?

1. Objective helplessness, 

   1. detecting behavioral control

1. What do mPFC projections to the dorsal raphe play an important role in ?

1. subjective helplessness, 

   1. determining future reactions to aversive stimuli