Limbic System Flashcards
Limbic system controls …
mood, emotion, feelings, and motivation
Limbic system pathways:
Hippocampus –> Mamillary body and Septal nuclei
Fornix
Limbic system pathways:
Mamillary body –> anterior N. Thalamus
mamillo thalamic tract
Limbic system pathways:
Amigdala –> Septal nucleus
Stria Terminalus
Limbic system pathways:
Midbrain via hypothalamus –> Forbrain
Medial forebrain bundle
Norepinephrine (NE) is made in what area of the Pons
Locus ceruleus
Serotonin (5HT) is made in what area of the midbrain and pons
Raphe nuclei
These hormones are involved in arousal and sleep wake cycles
Norepinephrine
Serotonin
Dopamine (DA) is active in what system and has what effect?
mesolimbic system, rewarding effect
The ventral tegmental area (VTA) sends DA neurons to…
nucleus accumbens, medial prefrontal cortex, amygdalal, septal nuclei
These drugs block DA reuptake which increases the conc. of DA at the synapse
cocaine and amphetamine
DA receptor blockers
decrease drug seeking behavior
lesion in the ventral tebental area or nucleus accumbens leads to
decrease drug seeking behvaior
Acetylcholine (ACh) is made in the
nucleus basalis and septal nucleus (both are lost in alshimers disease)
amygdala plays a role in
fear conditioning
lesions in the amygdala:
prevents fear conditioning
The following are characteristics of what disease:
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)
Prefrontal Lobe Syndrome
The Dorsolateral PFC plays a role in …
working memory
executive function
The Orbital frontal cortex (OFC) plays a role in
amygdala projection
The prefrontal cortex is ________ to the amygdala which is __________ to the hypothalamus
inhibitory
excitatory
lesion of the hippocampus can cause
anterograde amnesia (no new memories) temporally graded retrograde amnesia (loss of old memories)
Lesion of the hippocampus can cause
explicit or declarative memory loss
sematic (facts) and episodic (experiences) memory loss
lesion of the hippocampus will not cause loss of …
implicit memory (procedural or non declarative)
The following are characteristics of what disease;
impaired recognition of emotion in facial expressions
inability to judge “like” emotions (fear vs. anger, supprise vs. happy)
memory loss especially of information with emotional content
Urbach-Wiethe disease
dysfunction in the amygdala
The following are characteristics of what disease;
re-experiencing phenomena (flash backs)
avoidance of situations parallel in initial trauma
hyperarousal (hypervigilance leads to increased anxiety)
Post Traumatic Stress Disorder (PTSD)
Etiology of PTSD
increased activity of the amygdala
decreased activity in the medial prefronal cortex
(medial prefrontal cortex inhibits the amygdala)
Schizophrenia
Symptoms:
Positive: delusions, hallucinations (treatment only targets)
Negative: Social withdrawal
hypothesis that schizophrenia is due to increased DA receptor activity
Dopamine hypothesis
anti-psychotic that blocks DA receptors
Haloperidol
Side effects: parkinsonian like motor dysfuction
atypical anti-psychotic
blocks DA receptor
blocks 5HT receptor
blocks glutamate reuptake
clozapine
“glutamate hypothesis” phencyclidine (PCP) (angel dust) blocks what receptor
blocks NMDA glutamate receptor
Tx: increase glutamate receptor activity
Neurochemica basis for depression:
“monoamine hypothesis”
decrease NE and or 5HT receptor activity
anti-depressants:
monoamine oxidase (MAO) inhibition
tricyclics (Imipramine)
SSRIs (Fluoxetine)
anti-depressant:
blocks reuptake of NE and 5HT
Tricyclics (Imipramine)
anti-depressant:
block reuptake of 5HT
SSRIs (Fluoxetine)
The following are characteristics of what disease;
disorder of immediate memory
disorientation in space and time
confabulation –> fabrication
Korsakoff’s syndrome
causes of korsakoff’s syndrome
chronic alcoholism vitamin deficiency (B1 Thiamine)
what part of the limbic system is damaged in korsakoff’s syndrome
mammillary body or mamillo thalamic tract
The following are characteristics of what disease;
oral tendencies (all objects in the mouth) changes in emotions (amigdala damage) hypersexuallity (pathway to hypothalamus) visual agnosia (psychotic blindness, inability to discriminate visual stimulus)
Kluver-Bucy Syndrome (amygdala, hippocampus, and temporal cortex)
The following are characteristics of what disease;
loss of memory
mood disorders; anxiety and depression
loss of motor function
complete loss of cognitive function
Alzheimer’s dementia
Alzheimer’s dementia etiology
loss of cholinergic input to the hippocampus
loss of neurons in multiple brain areas
presence of neurofbrillary tangles (NFTs: phosphorylated tau proteins) and Beta-amyloid plaques
Treatment for Alzheimer’s dementia that blocks acetochoinesterase
Donepezil (aricept)
The following are characteristics of what disease;
progressive neuordegenerative disease caused by repeated head trauma
memory impairment: anterograde amnesia
executive dysfunction: goal-directed behaviors
depression
apathy
loss of impulse control, increase in aggressiveness
Chronic Traumatic Encephalopathy (CTE)
Etiology of Chronic Traumatic Encephalopathy (CTE)
brain atrophy
NFTs present
