Limbic system - emotion

Question 1

Papez’s circuit

Answer 1

mammillary bodies –> mamillothalamic tract –> anterior nucleus of the thalamus –> cingulate gyrus –> hippocampus –> entorhinal cortex –> fornix –> mammillary bodies

Question 2

Limbic system structures involved in memory

Answer 2

Hippocampus, orbitofrontal cortex, amygdala, ventral striatum (nucleus accumbens), VTA

Question 3

Cognition

Answer 3

a faculty for the processing of information, applying knowledge, and changing preferences. Involves memory, attention, problem solving, planning

Question 4

Emotion

Answer 4

complex psychophysiological experience of an individual’s state of mind as interacting with biochemical and environmental influences.

Involves physiological arousal, expressive behaviors, conscious experience

Question 5

Mood

Answer 5

affective state. more unfocused than “emotion”.

Involves a tone and intensity and a structured set of predictions about future experience of reward or punishment

Question 6

Role of amygdala in memory

Answer 6

formation and storage of memories associated with emotional events

Question 7

fear conditioning

Answer 7

sensory stimuli –> basolateral complexes of the amygdalae (BLA) –> central nucleus of amygdalae (CEA) –> associations with memories of the stimuli

Question 8

What process mediates the association between stimuli and the aversive events they predict?

Answer 8

LTP

Question 9

What are the the expressions of emotion mediated by CEA?

Answer 9

immobility, tachycardia, tachypnea, stress-hormone release

Question 10

Process of amygdala influencing adrenal action

Answer 10

Bed of stria terminalis –> hypothalamus –> mediated release of corticotropin-releasing hormone (CRH) from pituitary –> epinephrine and cortisol release from adrenal gland

Question 11

Damage to amygdala

Answer 11

impaired expression of Pavlovian fear conditioning

Poor performance on Iowa Gambling Task (impaired registration of emotional impacts of rewards and punishments caused by specific behaviors

Question 12

Appetitive (positive) conditioning

Answer 12

cells in BLA –> nucleus accumbens of ventral striatum

Question 13

Fear extinction

Answer 13

medial prefrontal cortex –> stimulated intercalated cell masses –> GABA release to CEA –> blocked CEA activity (LTD) –> suppressed triggering of fear response

Question 14

Ventral striatum (nucleus accumbens) and VTA

Answer 14

reinforce behaviors that elicit a reward

Question 15

Mechanism of reward signaling

Answer 15

Dopaminergic neurons in VTA –> dopamine to nucleus accumbens in ventral striatum –> VMPFC –> nucleus accumbens –> reinforced behavior

Question 16

VMPFC-nucleus accumbens loop

Answer 16

network that can, through the presence or absence of DA, reinforce or reduce the activity in networks that generate predictions about risks/rewards of a given behavior.

Excess DA –> reinforcement of networks active during the behavior that produced the DA surge

Question 17

What is one of the hallmarks of drug addiction?

Answer 17

Drug use (cocaine) –> excessive DA release to VMPFC loop –> excessive reinforcement of drug use

Question 18

Lesions to VMPFC

Answer 18

characteristic performance on Iowa Gambling Task:

patients cannot predict consequences –> choose cards from “bad” decks –> money loss