N: Limbic System Flashcards
Limbic system generates ___ and ____ from sensory inputs
feelings /emotions
Limbic system is evolved to promote ____ so activity varies depending on physiological need
promotes survival
so activity varies on physiological need
Limbic system bridges the __ and ___
autonomic / voluntary responses to environmental change
LImbic system consists of what 2 thigns?
- limbic cortex
2. subcoertical nuclei
Limbic cortex
Allocortex of ______ (___ layered)
Mesocortex of _____
3 layered allocortex of hippocampus and septal area
mesocortex in parahippocampus gyrus, cingulate, insula
What are the subcortical nuclei of the limbic system>
amygdala, hypothalamus
nucleus accumbens
reticular formation
Limbic system: Amygdala is responses for ___
emotional responses
Limbic system: Hippocampus is responsible for ___
learning and memory
HIPPOCAMPUS AFFERENT
Entorhinal cortex gets information from olfactory areas (____) and other areas (____)
olfactory - minor
other - major
HIPPOCAMPUS AFFERENT
Input from septal nuclei does what?
modulates whether information in the hippocampus will be retained
What are the 3 distinct zones of the hippocampus?
- dental gyrus
- hippocampus proper
- subiculum
Hippocampus proper aka ___
cornu ammonis (amin’s horn)
The subiculum is the transition between ____ and ____
hippocampus proper and adjacent parahippocampal cortex
AFFERENT HIPPOCAMPUS:
1. Afferent fibers from ___ sends to ____
sensory cortex –> entorhinal cortex
AFFERENT HIPPOCAMPUS
2. Entorhinal cortex projects to ____
This is via ____ pathway
dental gyrus
via perforant pathway
What is the perforant pathway>
entorhinal corex to dental gyrus
AFFERENT HIPPOCAMPUS:
3. Denta neurons project to ____
CA3 of hippocampus proper
AFFERENT HIPPOCAMPUS:
4. CA3 of hippocampus proper projects to ___ and __
FIMBRIA
CA1 of hippocampus proper
AFFERENT HIPPOCAMPUS:
5. CA1 of hippocampus proper projects to ___
subiculum
AFFERENT HIPPOCAMPUS:
6. Subilculum projects to ____
Via ___ pathway
FIMBRIA
via alvear pathway
What is the alvear pathway?
Subiculum to fimbria
AFFERENT HIPPOCAMPUS:
7. Subiculuar neurons project to ___
entorhinal cortex
AFFERENT HIPPOCAMPUS:
8. Entorhinal cortex projects to ____
sensory cortex
What are the 2 major EFFERENTS of the hippocampus?
- alvear pathway (subiculum to fornix)
2. entorhinal cortex going to cerebral cortex
The ___ is the direct continuation of the fimbriae
fornix
The fornix contains axons from what 2 structures?
subiculum and CA3 of hippocampus
The fornix has a long course underneath the ___
corpus callosum
THe ___ arches up from the hippocampus as a part of the fornix
crus
The 2 crus of the fornix join, forming a ____
This happens near the ____
forming a body (trunk)
this happens near hippocampal commissure
Fornix trunk divides into 2 ____
These split near the ___
2 commissures
These split near the anterior commissure
What are the 2 commissures (and what areas) after the fornix trunk (body) divides
- precommisural fibers (septal area)
2. post-commisural fibers (hypothalamus, mamillary body)
PAPEZ CIRCUIT:
1. Neurons in ____ projec tbackwards
cingulate gyrus
PAPEZ CIRCUIT:
2. Neurons from cingulate gyrus reach the ____
entorhinal cortex
PAPEZ CIRCUIT:
3. Entorhinal corttex projections into the ___
hippocampus
PAPEZ CIRCUIT:
4. Hippocampus projects into the ____
fornix
PAPEZ CIRCUIT:
5. Fornix projects into the ____
mamillothalamic tract
PAPEZ CIRCUIT:
6. Mamillothalamic tract projects from _____ to ____
from anterior nucleus of thalamus to cingulate cortex
What is short term memory?
hold information briefly in mind while you need it
ex: a telephone number
What is long-term memory?
What are the 3 types of long-term memory?
Stored information that can be retrieved
- explicit memory
- semantic memory
- implicity memory
What is explicit memory
type of long term memory
recall facts/events
aka declarative memory/episodic memory
Explicit memory aka ___ aka ___
declarative memory
episodic memory
What is semantic memory
type of long term memory
pertains to spoken/written words
extended to knowledge of facts/concepts
What is implicit memory
type of long term memory
performing a learned mortor function like riding a bike
What is working memory
needed for a task at hand, driving along a known route
What is “consolidation”
process of storing a new information in long-term memory
Novel facts are related from sensory areas to hippocampus for encoding, processed, and encoded information is sent back to ____.
association area it came from
Bilateral removal of hippocami impaired ___ memory
delcarative memory
Bilateral removal of hippocampi, impairing declarative memory… Could not form new: _____
episodic memories (past personal experiences)
semantic memories (ideas, concepts not related to personal experiences like state capitals
Bilateral removal of hippocampi, impairing declarative memory… Could still use _____
working memory
HM could use new skills
Bilateral removal of hippocampi, impairing declarative memory…
Had impaired declarative memory
_____ brain
HMs
The amygdala is in the ____ lobe
anterior, medial temporal lobe
The amydala merges with ____
periamygdaloid cortex
The periamygdaloid cortex is part of the ____
uncus
The amygdala has ___ nuclear groups
3
What are the 3 nuclear groups
medial
central
basolateral
AMYGDALA
medial nucleus has __ inputs
olfactory
AMYGDALA
central ncuels has ___ inputs
hypothalamus, PAG
AMGDALA
Basolateral nucleus has ___ inputs
cortex, central nuclei
All sensory association areas have direct input to the ___
basolateral nucleus of amygdala
All sensory association areas are linked to the ____ via association fibers
so sensation can be cognitively evlauated
prefrontal cortex
Visual areas stimulating the amygdala can stimulate ___
***this happens only if the amygdala / prefrontal cortex association fibers are not working properly
phobias / anxiety states
Visual areas stimulating the amygdala stimulate phobias / anxiety states
This happens only if ______
amygdala and prefrontal cortex association fibers are not working properly
Most nuclei receiving amygdala afferents are located ____
so collectively terms ____
laterally
so collectively termed “lateral nucleus”
Amygdala afferents from the orbital cortex / cingulate do what?
generate sense of emotional / physical discomfort
Amygdala afferents from the brainstem and PAG do what?
generate visceral sensation
Amygdala afferents from cortex / thalamus do what?
sensation from vision, taste, hearing, somatosensory
Amygdala afferents from olfactory bulb and cortex do what?
sensation of olfaction
What are the main 2 pathways in the amygdala?
- stria terminalis
2. ventral amygdalofugal pathway
The stria terminalis is from the __ and the ___
hypothalamus and septal nuclei
The ventral amygdalofugal pathway is from the ___ (4 things)
thalamus
hypothalamus
orbital and anterior cingulate gyrus
Stria terminalis emerges from the ___
central nucleus
After the stria terminalis emerges from the central nucleus, it follows ____
the curve of the caudate
After the stria terminalis fibers have followed the curve of the caudate, it goes into the ___
septal areas and hypotahalmus
After the stria terminalis have gone through the septal areas and hypothalamus it goes ____
medial forebrain bundle and central tegmental tract
The bed nucleus is an _____
extended amygdala
it may be more active in anxiety than the amygdala
The amygdala can trigger a _____ reaction to fear
sympathetic
Amygdala going to PAG (medulla/raphespinal tract) triggers ____
antinociception
Amygdala going to PAD (medullary reticulospinal tract) triggers ___
freezing
Amygdala going to norepinephrine medullary neurons projected to lateral gray horn triggers ____
increased heart rate and blood pressure
Amygdala going to hypothalamus/dorsal nucleus of vagus (heart) triggers ___
decreased heart rate, fainting
Amygdala going to the hypothalamus to release corticotropin RH triggers ___
stress hormone secretion
Amygdala going to parabrachial nucleus to medullary respiratory nuclei triggers ____
hyperventilation (panic attacks)
Kulver bucy syndrom
____ lobe injury involving ____
bilateral temporal lobe injury
involves the amygdala, parahippocampus gyrus
Symptoms of kulver bucy syndrome
fearless, placid, no emotional reactions, don’t respond to threats from others, don’t flee from threats
males become hypersexual, indiscriminate, will have sex with inaminate objects and different species
Inordinate attention to all sensory – sniff and orally examine everything.
If they can eat it, they will eat it
May pick up the same object repeatedly as they seem to recognize ntothing (visual agnosia) from VISUAL CORTE DAMAGE
what is visual agnosia
- damage to what causes>
- what syndrome is it associated with?
pick up same object repeatedly and seem to recognize nothing
visual associated cortex damage
kluver bucy syndrome
Nucleus accumbens aka ___
ventral striatum
Nucleus accumbens stimulates a sense of ___
well being
The “high feeling” associated with nucleus accumens (ventral striatum) is associated with ____ from ____
this is released into ___
dopamine from ventral tegmental area
released into nucleus accumbens
Dopamine is released from ____ into ____
gives a “high feeling”
from ventral tegmental area in midbrain to nucleus accumebns (ventral striatum)
When dopamine is released from tegmental area of midbrian into nucleus accumbens (ventral striatum), it influences our behavior…. This leads to ____
behavior that stimulates more REWARD AKA LOOP
LIMBIC LOOP IN BASAL GANGLIA
What is the limbic loop in basal ganglia?
When dopamine is released from tegmental area of midbrian into nucleus accumbens (ventral striatum), it influences our behavior to do more rewards-driven tasks
LOOP!
