Limbic System

limbic cortex

cingulate gyrus

parahippocampal gyrus

medial orbitofrontal cortex

entorhinal cortex

limbic nuclei

amygdala

hippocampus

septal nuclei

thalamus/hypothalamus

mammillary bodies

nucleus accumbens

limbic system connections

fornix

mammillothalamic tract

cingulum

medial forebrain bundle

Where is the amygdala located?

near the temporal pole

where does the amygdala receive its projection?

olfactory system and temporal cortex

the amygdala has connection to ___

septum

hippocampal formation is made up of

hippocampus, dentate gyrus, and parahippocampal gyrus of the temporal lobe

where does the hippocampal formation receive its fibers and project where?

fibres from the entorhinal cortex an project via the fornix tot he mammillary body of the hypothalamus

what is the hippocampal formation made of?

interlocked C-shapes: CA1-CA3 and dentate gyrus

Afferents and efferents of the hippocampus are bundle together in the same ___

paths

inputs to the hippocampus

subiculum directly

to EC, then subiculum

(from amygdala to EC via amygdalofugal pathway)

output from hippocampus

back to subiculum, then to cortex

to fornix, to subcortical area

what becomes the fornix?

fimbriae converge in the midline

what structures does the columns of the fornix pass through?

mammillary bodies (postcommissral) and to septum (precommissural)

korsakoff’s syndrome

memory loss caused by lack of thiamine

People with korsakoff syndrome may ___

confabulate

what is confabulate ?

fill gap in memory with falsification

cingulate gyrus receive its input from

anterior nucleus of thalamus

frontal and somatosensory and anterior visual cortex

cingulate gyrus connect to parahippocampal gyrus via

cingulum bundle

function of cingulate gyrus

emotional processing, learning, and emotional memory

attentional flexibility

empathy

in schizophrenic, the cingulate gyrus has

abnormal structure and function

what kind of information does the amygdala receive?

preprocessed sensation - tactile, visual, auditory, visceral

where does the amygdala project its information?

cerebral cortex and hypothalamus

function of amygdala

anger and fear recognition

limbic system and stress

switches from slow, thoughtful PFC regulation to reflexive, rapid amygdala emotional responses

septal nuclei serve as

relay of hippocampus to hypothalamus

function of septal nuclei

septal rage and emotional memory

efferent connection of septal nuclei

hypothalamus and prefrontal cortex

another name for nucleus accumbens

ventral striatum

function of nucleus accumbens

reward and pleasure

where does the nucleus accumbens project from

VTA through medial forebrain bundle

function of limbic

fighting and fleeing

feeling

forgetting

sexual

wernicke’s encephalopathy

deficiency of thiamine leads to capillary hemorrhages in the upper brainstem and limbic structures and falls into confusion and coma

Which structure is damaged in Klein Levin syndrome ?

hypothalamus

which structure is damaged in kluver bucy syndrome?

amygdala

klein levin syndrome

hypersomnia, episodic abrupt onset with flu like symptoms, excessive eating, irritability, uninhibited sex drive, hallucination

kluver bucy syndrome

flattened emotional affect, difficulty recognizing faces, increased sexual behavior

limbic encephalitis

seizures, apathy, confusion, short term memory difficult, emotional lability, sexual disinhibition, episodic agitation

right hemisphere stroke and smiling

natural smile and no basal ganglia damaged

natural (spontaneous) circuit is intact