Neuro 74: Memory, emotions, & the brain

Question 1

Sensory memory

Answer 1

• encodes sensory stimuli

- 0-2 sec

Question 2

Short term memory

Answer 2

• most recent info

- 30 sec

Question 3

Working memory: what is it and what 2 locations is it stored?

Answer 3

• brief storage of verbal, visual, and spatial info
• linked to reasoning, comprehension, learning, and long term memory
• cognitive function is assessed clinically by testing working memory
• stored = left and right parietal and prefrontal cortex

Question 4

Long term memory

Answer 4

-relatively permanent

Question 5

Semantic memory: what is it and where is it stored?

Answer 5

• memory of facts/general world knowledge
• form of long term memory
• stored = temporal lobe

Question 6

Episodic memory: what is it and where is it stored?

Answer 6

• memory of personal events, linked to place/time
• form of long term memory
• stored = distributed throughout the association areas of the cortex

Question 7

Procedural memory: what is it and where is it stored?

Answer 7

• memory of how to do something (motor)
• form of long term memory
• stored = motor association complex

Question 8

What 2 types of memory are often affected by disease proesses?

Answer 8

1. working memory

2. episodic memory

Question 9

What is usually impaired to cause the memory deficits seen in dementia?

Answer 9

-consolidation

Question 10

Consolidation

Answer 10

-the process of taking short term memories and making them long term memories

Question 11

How is episodic LTM stored?

Answer 11

• via consolidation which includes anatomical changes at synapses that require protein synthesis
• hippocampus transfers episodic info to cortex functional areas –> becomes a more stable LTM

Question 12

Where is the hippocampus?

Answer 12

• lg structure that looks like a banana or jelly-roll

- found deep in the temporal lobe, in the temporal horn of the lateral ventricle

Question 13

Papez circuit

Answer 13

• involves memory
• hippocampus –> fornix –> mamillary body (hypothalmus) –>anterior nucleus of the thalmus –> cingulate gyrus –> entorhinal cortex –> hippocampus
• function of this pthwy is not completely known –> BUT if the circuit is damaged anywhere then consolidation will not be able to happen

Question 14

What is special about hippocampal neurons? + what is this enhanced and impaired by?

Answer 14

• new neurons are generated in the hippocampus throughout life
• have stem cells that undergo differentiation and become new neurons
• effects memory consolidation
• enhanced by: exercise and mental stimulation
• impaired by: depression, stress, ages, dementia

Question 15

Working memory deficits: where, effects, causes?

Answer 15

• caused by lesions in the parietal cortex, the frontal cortex, or their interconnections in white matter
• impairs the temporary storage of verbal, visual, spatial info & its processing & its manipulation
• can be caused by stroke, trauma, or degenerative diseases

Question 16

Episodic long-term memory deficits: where, effects, causes?

Answer 16

• damage to the sensory association areas
• causes agnosia
• can be caused by stroke, trauma, cortical degenerative diseases

Question 17

Agnosia

Answer 17

• loss of ability to recognize objects, persons, sounds, shapes, or smells –> loss of knowledge about common objects
• the sense is NOT defective and there is NO memory loss

Question 18

Effects of hippocampal lesions

Answer 18

• anterograde amnesia
• What’s intact = short term, working memory, already-stored memories, ability to learn new motor tasks (but have no recollection of learning them)
• What’s not intact = storing new episodic memories
• needs to be a bilateral lesion to get problems!
• can be caused by: stroke, trauma, neurodegen diseases

Question 19

Anterograde amnesia

Answer 19

• inability to store new episodic memory

- caused by bilateral lesion in the hippocampus!

Question 20

Wernicke-Korsakoff’s syndrome

Answer 20

• chronic alcoholics w/ thiamine deficiency get damage to their mammillary bodies
• causes memory consolidation problems

Question 21

Memory & olfaction

Answer 21

-the olfactory cortex is adjacent to underlying hippocampus –> so some smells can form long lasting potent memories

Question 22

Amygdala

Answer 22

• lg nucleus in the temporal lobe at the anterior end of the hippocampus
• lies beneath the uncus
• has a majr role in: recognizing & responding to threatening stimuli
• part of the limbic system

Question 23

Limbic system

Answer 23

• limbus = border
• on the border btwn the cortex and the hypothalmus
• integrates emotion, memory, and autonomic responses

Question 24

What are the 4 effects of the amygdala being stimulated?

Answer 24

1. behavioral freezing -via the brainstem
2. autonomic activation -via hypothalmus –> + symps
3. consoldates aversive aspects of negative experiences
4. cortex-emotional awareness
   * *can get cycling btwn the + of the symps and the cortex emotional awareness!

Question 25

What can beta-blockers be used for?

Answer 25

-can break the cycle btwn the +symps and emotional awareness

Question 26

Effects of lesions in the amygdala?

Answer 26

-causes decrease in emotionality, loss of fear, and indifference to fearful stimuli

Question 27

Kluver-Bucy syndrome

Answer 27

- bilateral loss of the temporal lobe in experimental animals - effects: 1. placid behavior - loss of fear/agression --> due to loss of amygdala 2. males become hypersexual 3. psychic blindness - inability to recognize objects, but not blind --> from damage in the "what" stream 4. oral examination of objects

Question 28

Nucleus accumbens: where is it, what does it do?

Answer 28

- plays a role in reward and reinforcement behavior & also plays a role in regulating mood - important in motivation for behavior (why we do things) and addiction (why we continue to do things) - under the caudate nucleus - relies heavily on dopamine as an NT - influences behavior via connections w/ the prefrontal cortex

Question 29

Drugs effects on the nucleus accumbens

Answer 29

- some drugs (cocaine, opiates, and alcohol) will increase the effects of dopamine in the NA - this will reinforce and sustain the behavior --> addiction

Question 30

Only 2 locations of dopaminergic neurons?

Answer 30

1. midbrain = susbtantia nigra & ventral tegmental area | 2. hypothalmus

Question 31

What are the 4 dopaminergic projections of the brain?

Answer 31

1. mesocortical = frontal lobe fctn 2. mesolimbic = to nuc accumbens 3. nigrostriatal = to BG 4. tubero-infundibular = inhibits prolactin release

Question 32

Ventral tegmental area

Answer 32

- dopaminergic | - axons from here influence the cortex and motivated behavior via the nuc accumbens