Exam #6: Limbic System Flashcards Preview

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Flashcards in Exam #6: Limbic System Deck (23)
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1
Q

What is emotion? How would you define emotion?

A

Emotion is defined as “powerful subjective feelings & their associated physiological states”

**This implies that there are neurobiological connections between the cortex (subjective feeling) & systems that produce corresponding physiological states (endocrine)

2
Q

What are the major functions of the limbic system?

A

1) Production of emotional responses
2) Memory
3) Homeostasis

3
Q

What are the functions of the hypothalamus?

A

1) Governing/ monitoring internal homeostasis

2) Mediates raw & reflexive emotionality via the ANS

4
Q

What are the functions of the amygdala?

A
  • Fear
  • Interpretation of facial expression
  • Motivation & emotion
  • Learning & memory (some)

Integrative center for emotions, emotional behavior, and motivation

5
Q

What is the function of the limbic cortex?

A

Governs the efficient, effective, & safe satisfaction of limbic needs

6
Q

What structures compose the limbic cortex?

A
  • Anterior cingulate cortex (Acc)
  • Orbitofrontal cortex
  • Medial prefrontal cortex (mPFC)
  • Insula
7
Q

What are the functions of the hippocampus?

A

Memory

  • Contextual influences on emotion
8
Q

What is the function of the nucleus accumbens?

A

Motivation and reinforcement

9
Q

How does the amygdala interact with the cerebral cortex to produce emotional behaviors?

A

The mPFC regulates the amygdala e.g. preventing yourself from losing your temper

10
Q

Describe fear conditioning.

A

This is an experimental procedure in rats with 2 phases:

1) Habituation
2) Conditioning–shock paired with sound (conditional stimulus)
3) Testing–presentation of CS (sound) only

*****Fear responses are seen in response to the sound only

11
Q

What is the reward system?

A

This is the Limbic Loop of the Basal Ganglia

  • DA from the VTA to NAcc serves are a reward signal
  • Normally promotes motor progams to acquire beneficial rewards e.g. food, water, sex, love…etc.
12
Q

What is the neurobiological basis of drug addiction?

A

Drugs of abuse target the dopaminergic reward pathways and damped the reward response to natural stimuli, simultaneously increasing the response to addictive drugs

13
Q

What does a lesion to the amygdala result in?

A

Flat affect & docile behavior

14
Q

What is the primary output of the limbic system?

A

Hypothalamus

15
Q

Where is dopamine produced in the limbic system? Where do dopaminergic neurons project in the limbic system?

A

DA is produced in the mesolimbic system; primary projections include:

1) Ventral Tegmental Area
2) Nigrostriatal pathway

16
Q

What is the Ventral Tegmental Area (VTA)?

A

NAcc, mPRC & Septal Nuclei

17
Q

What is the Nigrostriatal pathway?

A

SN to striatum

18
Q

What are two unique characteristics of the hypothalamus?

A

1) Exerts influence through both synaptic & circulatory connections
2) Exhibits sexual dimorphism i.e. different functions/hormones in different sexes

19
Q

What are the three major components of the amygadala?

A

Basolateral
Central
Corticomedial

20
Q

What is the biggest part of the amygdala & why?

A

Basolateral region is biggest in humans

*****This is the input region–it has to be large to accommodate all of the information coming in from the cortices

21
Q

What are the neural mechanisms underlying fear conditioning?

A

US

1) US sensation is carried via sensory pathways to somatosensory cortex
2) Somatosensory cortex projects to the amygdala
3) Amygdala’s connections with:
- CG= freezing
- LH= autonominc resoponse
- PVC= hormones

CS

1) Sensation of CS to amygdala
2) Pairing with US
- ->Same responses

22
Q

What is the neural basis for empathy?

A

Mirror neurons

23
Q

Describe the presentation of an mPFC lesion.

A
  • Apathetic
  • Impulsive
  • Poor judgement
  • Depressive behavior
  • Mania

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