lecture 10: limbic system Flashcards
limbic lobe is a ______ structure that forms a ______ boundary when including the __________
cortical
circular
olfactory bulb & tract
limbic lobe does not share a boundary with which lobe?
occipital
what are 3 main structures of the limbic lobe?
- cingulate gyrus: ant & post
- parahippocampal gyrus: entorhinal cortex
- uncus: piriform cortex – primary olfactory cortex
the piriform cortex used to be called the __________ because it was thought that it played a role with the olfactory area but now it was found it doesn’t anymore
rhinencephalon
what structure is directly related to the limbic system but is not classified as part of the limbic system?
cerebellum
true or false. we still use the Papez circuit to define the functions of the limbic system
false –> more things added to it. now called the spiral model
what is emotion?
integrated physiological changes, behavioral reactions and feelings
what are the two theories of emotion classification?
1) distinct _____ basic emotions
2) _______ with arousal level w/ neg. to post. valence –> aka you never have ________ emotion
1) 6
2) spectrum ; neutral
the hypothalamus forms the ________ wall of the _____ ventricle
it is located _______ to optic chiasm
anterolateral ; 3rd
superior
life and death functions of the hypothalamus:
- homeostasis/initiation of drives (individual survival)
- reproduction (species survival)
- bridging endocrine and nervous systems
function of the 6 hypothalamic nuclei:
1. lateral nucleus:
2. ventromedial nucleus
3. posterior nucleus
4. anterior nucleus
5. paraventricular nucleus
6. supraoptic nucleus
- hunger center
- satiety center
- heating center
- cooling center
- produces oxytocin
- produces vasopressin ADH
neurohypophysis:
- location:
- developed from:
- stores & releases which two hormones?
- functions of these two collectively:
- posterior pituitary
- diencephalon
- oxytocin (myometrium contraction & breast smooth muscle) AND ADH (water absorption & increase BP)
- mating, bonding, brain development
adenohypophysis:
- location:
- developed from:
- what carries hormones to adenohypophysis?
- which hormones are released to the adenohypophysis?
- anterior pituitary
- posterior oral cavity (Rathke pouch)
- hypophysial portal vein
- thyrotropin-releasing, growth hormone-releasing, growth hormone release-inhibiting, corticotropin-releasing, gonadotropin-releasing, prolactin-releasing
temperature regulation reflex (intrinsic):
- specialized _______ neurons in hypothalamus
- normal blood temp. setpoint:
- when blood flows through the neurons & temp is detected, if the temp is lower than the setpoint, what is activated?
- when blood flows through the neurons & temp is detected, if the temp is higher than the setpoint, what is activated?
- rostral (ant.) hypothalamus function:
- caudal (post) hypothalamus function:
- temp-sensing
- 37 deg C
- posterior nucleus (increase heat)
- anterior nucleus (sweat to decrease heat)
- heat dissipation (cool)
- heat conservation/production (heat)
what is happening when our body produces a fever?
cytokines/bacterial endotoxin increases the body temp past the setpoint –> increased temp will kill viruses
what is happening to women’s bodies in postmenopausal syndrome?
irregular body temp setpoint –> setpoint changes due to loss of hormones
water balance reflex (neurohumoral):
- specialized ________ neurons in hypothalamus
- if plasma osmolarity is too high _____
- if plasma osmolarity is too low _____
- osmolarity-sensing
- increase ADH –> keep more water in
- decrease ADH –> pee too much
_______ blocks ADH release –> urinates too much
alcoholism
not enough ADH is released into the blood in a patient with ________
diabetes insipidus –> pee all the time
Baroreceptor reflex (extrinsic):
- maintains:
- afferent signal:
- efferent signal to counteract:
- effect:
- blood pressure
- baroreceptors in carotid sinus (CN IX) and aortic arch (CN X) (increase BP)
- CN X
- decrease HR/BP
what structure can over-ride the baroreceptor reflex? typically needed in fight or flight situations when we need an increase in HR
hypothalamus
functions of projections of the hypothalamus:
- medial frontal lobe:
- cerebellum:
- fornix –> amygdala:
–> hippocampus:
- thalamus:
- spinal cord/brainstem:
- regulating drives/emotion
- emotion/motor skill memory –> integration of somatic and visceral motors
- 1: emotion 2: declarative memory
- coordination
- homeostasis and motor execution
location of amygdala:
- ______ to inferior horn of lateral ventricle
- ______ to optical tract
- _______ to hippocampus
- medial
- lateral
- anteromedial
3 clusters of nuclei in amygdala:
- medial
- central
- basolateral
- olfactory tract
- hypothalamus and brainstem nuclei
- different cortex region and sensory pathway
amygdala function in emotional learning:
- _________ through experienced aversive stimuli directly (touch hot oven)
- video, drawings, warnings
- other emotional learning such as
- memory enhancement effects have direct projection to ______
- memory enhancement effects function:
- fear conditioning
- learned experience
- reward-based learning
- hippocampus
- improving encoding, prevent extinction
fast track pathway:
- sensory signals conducted to the ______
- projects to the _______ then initiates _______
- example?
thalamus
amygdala ; motor reflexes
- you see a toy spider (but you think it’s real so you jump real fast)
fast track pathway is the _____ alert system
–> includes all ______ modalities
1st
sensory
cortico-amygdaloid pathway aka _____ pathway
- you generate more information & analyze the situation –> you ____
slow
relax
** not only one emotion center or purely emotion of fear
nucleus accumbens:
- overall function:
- location
- part of the _____
- function of the shell:
- function of the core:
- major reward center
- ant. & ventral to the caudate and putamen
- ventral striatum
- pleasure
- want/drive
reward seeking pathway:
dopamine from __________ –> nucleus accumbens –> _____ ____ thalamic nuclei –> medial/ventral _______ ______ and anterior ______ ______
ventral tegmental area –> N.A –> dorsal medial thalamic nuclei –> med./vent prefrontal cortex and ant. cingulate gyrus
aversion pathway:
______ projections from __________ to ___________ and __________
direct
ventral tegmental area —> medial prefrontal cortex and anterior cingulate gyrus
Henry Molaison:
- had several seizures resulting in bilateral temporal lobectomy. what did he lose & function loss?
hippocampus, most of amygdala and entorhinal cortex
–> seizure managed but memory is compromised
as a result of the temporal lobectomy, Henry also lost some cerebellum. what medication treatment did he take for a while and what negative effect did that have on him?
- phenytoin for seizures
- resulted in cerebellar atrophy
two parts of the hippocampus:
1. dentate gyrus:
–> contains granule cells and _______ which regenerate the granule cells
- hippocampus proper (cornu ammonis):
–> contains ______ cells
- stem neuron cells
- pyramidal cells
main input to hippocampus is from:
main output from hippocampus proper is:
entorhinal cortex
fornix
which type of amnesia (memory loss)?
- no new memory formed ; can be short period like concussion or forever
- loss of old memory ; generally short period
- anterograde amnesia
- retrograde amnesia
two types of retrograde amnesia:
- loss of more recent memory but intact with much older memory
- damage of midline diencephalic structure, all memories impaired with various degrees
- temporal graded
- flat gradient
how does Alzheimer’s disease relate to amnesia?
varies from temporal graded to flat gradient amnesia
septal nuclei:
- 2nd location of having _______
- injury to this area causes:
- stem cells –> still only regenerate granule cells
- flat gradient amnesia
Korsakoff’s disease/psychosis:
- alcoholism abolished ______ and resulted in death of _______
- result of this disease:
–> mainly ______ but some _______ amnesia
- VitB1 ; septal nuclei neurons (memory formation)
- confabulation : anterograde amnesia with old memory mixed up as new memory –> anterograde but some graded retrograde
dissociation of memory pathways results in _______.
a person with this (can/cannot) learn motor skills but can’t explain how
no more memory formed
can
what type of memory?
- limited capacity, temporary storage, new information under encoding, not technically considered short term memory
working memory
what type of memory?
- related to hippocampus and medial diencephalon, has two parts: episodic and semantic, a type of long-term memory, and functions for storage and retrieval of events, experiences, etc. w/ conscious awareness
declarative/explicit
what is episodic memory?
conscious recollection of personal experience about what/where/when it happened
–> donor and dry lab
what is semantic memory?
general world knowledge and facts learned
–> lecture
what type of memory?
- related to cerebellum/amygdala/basal nuclei and cerebrum, type of long term memory that influences behaviors, skills, etc. without conscious awareness
nondeclarative, procedural, implicit
learning and storage of memory:
- converting info for storage through short term memory
- consolidation or transformation to long term memory
- recall vs recognition
- encoding
- storage
- retrieval
principle NO 1 for storage of memory
all happens at the same association cortex where 1st time experience and 2nd time of retrieval happens
principle NO 2 for storage of memory
dissociation of memory –> lose some part of memory
true or false. amnesia is a result if ANY one of these steps of memory is impaired.
true
