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Flashcards in Limbic System Deck (31)
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1
Q

What path does the fornix take?

A

From the hippocampus to the mamillary body, sepal nuclei.

2
Q

What tract travels from the body of the mamillary body to the anterior thalamic nucleus?

A

Mamillo-thalamic tract

3
Q

What travels from the amygdala to the septal nuclei?

A

Stria terminalis

4
Q

What travels from the midbrain to the forebrain via the hypothalamus?

A

Medial forebrain bundle

5
Q

What travels from the hypothalamus to the brainstem and spinal cord, giving off branches to the pons, medulla, and spinal cord?

A

Dorsal longitudinal fasciculus

6
Q

Where does norepinephrine in the limbic system come from?

A

Locus ceruleus (LC) in the pons

7
Q

Where does serotonin (5HT) in the limbic system come from?

A

Raphe nuclei (Ra) in the midbrain, pons, and medulla

8
Q

What region in the mesolimbic system is associated with dopamine?

A

Ventral tegmental area (VTA); just medial to the substantia nigra. Axons from nucleus accumbens, medial prefrontal cortex, amygdala, & septal nuclei zip through here.

9
Q

What do cocaine and amphetamines do to dopamine levels?

A

-Cocaine blocks dopamine reuptake, thus increasing the concentration in the synaptic cleft. —Amphetamine blocks dopamine reuptake as well as promote secretion of dopamine.

10
Q

What neurotransmitter is associated with nucleus basalis and septal nucleus?

A

Acetylcholine. In alzheimers, Nucleus Basalis is lost, memory deficits. Acetylcholine is important in memory.

11
Q

What happens to learned and conditioned behavior if the amygdala is lesioned?

A

No conditioning can happen and there is immediate extinction of learned behavior.

12
Q

What symptoms are seen in a prefrontal lobe syndrome?

A
  • Impairment in goal directed behavior
  • Lack of emotion in decision-making (lack of risk aversion)
  • Poor social judgement (antisocial behavior)
  • Poor emotional control (increased impulsivity)
13
Q

What does the dorsolateral prefrontal cortex (DLPFC) play a major role in?

A

Working memory

14
Q

Why does the orbital frontal cortex play a major role in prefrontal lobe syndrome?

A

It is connected to the amygdala, inhibiting it. Without it, more prone to fits of emotion. Prefrontal cortex is inhibitory to the amygdala, which is excitatory on the hypothalamus.

15
Q

What is the hippocampus important in?

A

Memory consolidation, specifically explicit or declarative memory.

16
Q

What is anterograde amnesia?

A

No new memories

17
Q

What is temporally graded retrograde amnesia?

A

You can’t remember past events well in a graded fashion; recent past events are harder to recall then events long ago.

18
Q

Differentiate between semantic and episodic memories.

A

Semantic- facts
Episodic- experiences
*Hippocampus is needed for this

19
Q

What types of memory is the hippocampus not needed for?

A

Procedural or nondeclarative/implicit AKA motor memory

20
Q

What disease is indicative of:

  • impaired recognition of emotions (fear and anger)
  • Memory loss especially w/emotional content
A

Urbach-Wiethe disease (bilateral damage due to mineral deposit in amygdala)

21
Q
  1. Re-experiencing phenomena i.e. flashbacks
  2. Avoidance of situations that parallel initial trauma
  3. Hyperarousal i.e. increased anxiety..hallmark
A

Post Traumatic Stress Disorder (PTSD)

-Hyperactivity of amygdala, little inhibition by medial prefrontal cortex

22
Q

Fragmentation of mood, thought, and action.
Positive symptoms: Delusions, hallucinations
Negative symptoms: Social withdrawal

A

Schizophrenia (1% of U.S. population)

23
Q

What is the dopamine hypothesis of schizophrenia?

A

There is an increase in DA receptor activity.

-Amphetamine psychosis from taking amphetamines too long, lots of DA

24
Q

Treatments of schizophrenia?

A

Haloperidol: D2 receptor blocker. Causes Parkinson like disorder

Clozapine (atypical anti-psychotic):

  1. D2 receptor blocker, but leaves receptor fast
  2. 5HT receptor blocker
  3. Blocks glutamate reuptake, thus increased glutamate
25
Q

What is the glutamate hypothesis of schizophrenia?

A

Phencyclidine (PCP) aka angel dust blocks NMDA receptor, thus decreasing glutamate and causing psychotic symptoms. Treat by increasing glutamate.

26
Q

What are the symptoms of depression?

A

-Anhedonia: loss of interest in pleasurable/rewarding behaviors
-Sleep wake problems
-Social withdrawal
20% of women, 13% of men

27
Q

What are the treatments for depression?

A

Treat decreased NE and or 5HT receptor activity:

  • Monoamine oxidase inhibition
  • Tricyclics (Imipramine): blocks reuptake of NE and 5HT
  • Serotonin specific reuptake inhibitors (SSRIs) e.g. fluoxetine
28
Q
  • Disorder of immediate memory
  • Disorientation
  • Confabulation

*Damage to mamillary bodies or mamillo-thalamic tract

A

Korsakoff’s syndrome

-Chronic alcoholism associated with this because it ultimately leads to a vitamin b1 deficiency

29
Q
  • Oral tendencies
  • Changes in emotions (even keel, nothing bothers them due to loss of amygdala)
  • Hypersexuality (increased number and variety of sexual activities due to loss of pathways to hypothalamus)
  • Visual agnosia (AKA psychic blindness. Inability to discriminate visual stimuli due to lost input from visual cortex.)
A

Kluver-Bucy Syndrome: bilateral medial temporal lobe damage.

30
Q
  • Memory loss
  • Mood changes: anxiety and depression
  • Motor dysfunction
  • Complete loss of cognitive function
A

Alzheimers Disease (over 50% of ppl over 85)

  • loss of chlinergic input to hippocampus (antiacetylcholinesterases? don’t work well)
  • Loss of neurons in multiple brain areas
  • Presence of NFT and beta amyloid plaques
31
Q

What disease is caused by repeated head trauma and mimics prefrontal cortex damage?

A

Chronic traumatic encephalopathy (CTE)