limbic system Flashcards
wernicke-korsakoff syndrome
major causes is vitamin B1 deficiency and alcoholism
where is the damage that results in wernicke-korsakoff syndrome
mammillo-thalamic tract disruption
symptoms of wernick-korsakoff syndrome
no new memories
loss of memory
hallucinations
confabulation
what is the function of hippocampus
memory consolidation
motivation
location
where is the hippocampus?
in the medial temporal lobe
what are the three major division of the hippocampus?
dentate gyrus
CA3 (cornus ammon 3)
CA1 (cornus ammon 1)
major afferent of hippocampus?
perforant path
major efferent of hippocampus?
fornix
what is the intrinsic function of hippocampus?
trisynaptic circuit
trisynaptic circuit path
entorhinal cortex->perforant path->dentate gyrus->mossy fibers->CA3-> schaffer collaterals->CA1-> subiculum
two branches of the fornix
post commissural (circuit of papez) most goes here pre commissural
limbic amnesia
bilateral medial temporal lobe damage
damage mostly in hippocampus
signs of limbic amnesia?
cannot form new memories
can recall prior events
causes of limbic amnesia?
herpes head trauma stroke epilepsy drugs surgery
early stages of alzheimer’s disease signs
amnestic
reduced motivation
troubles navigating familiar places
general cognitive impairment
three major divisions of the amygdala
basolateral complex
corticomedial
central necleus
what are the two major efferents of the amygdaloid complex
amygdalofugal
stria terminalis
what is the function of basolateral complex
modulates motor function
what are the efferents of the basolateral complex?
amygdalofugal fibers to frontal cortex, basal ganglia, motor cortex
what is the function of the corticomedial and central nucleus?
autonomic functions
what is the efferent of the corticomedial and central nucleus?
stria terminalis to septal nuclei, autonomics, hypothalamus
amygdala signs
poor conditioned emotional response
poor recognition of fear, especially facial
**default is to be afraid
what is the cause of Kluver-Bucy syndrome?
bilateral lesions to the amygdala due to trauma, herpes, tumors
what are symptoms of Kluver-Bucy syndrome?
docility, overeating, hyperphagia (eating inapporpriate objects) eg: pica, hyperorality, hypersexuality, visual agnosia
circuit of papez starts at cingulate gyrus and goes where?
via the cingulum goes to entorhinal cortex
from the entorhinal cortex what is next in the circuit of papez?
via the perferant path to the hippocampus
from the hippocampus where to the efferents go?
the fornix to the mammillary bodies
mammillary bodies send information via the mammallo-thalamic tract to where?
anterior thalamus
the anterior thalamus uses the thalamo-cortical tract to send efferents where?
the cortex
