Hotzman- Limbic system Flashcards
(100 cards)
1
Q
Which structures directly or indirectly communicate with the hypothalamus or midbrain periaqueductal gray?
A
limbic structures
2
Q
What are the major structures of the limbic cortical areas:
A
Major limbic cortical areas:
- Parahippocampal gyrus
- Cingulate gyrus
- Prefrontal cortex*
- Temporal pole*
*Sources vary as to whether these are considered limbic structures
3
Q
Along with the major limbic cortical areas:Major limbic cortical areas: - Parahippocampal gyrus - Cingulate gyrus - Prefrontal cortex* - Temporal pole*
What other structures are included?
A
- Hippocampal formation
- Amygdala
- Septal area (nuclei)
- Hypothalamus*
4
Q
What are the 4 basic categories of limbic function (HOME)?
A
H- Homeostatic functions, including autonomic and neuroendocrine control
O- Olfaction
M- Memory
E- Emotions and drive
5
Q
What are the functions of these limbic system associated structures?
A
6
Q
The olfactory cortex delivers major inputs to which limbic system component?
A
hippocampal formation
7
Q
What 3 places to afferent fibers come from to end up in the prefrontal cortex?
A
All cerebral cortical regions
- All brainstem monoaminergic systems -
Other limbic system structures
8
Q
What 3 main areas do efferent fibers end up from the prefrontal cortex?
A
Temporal neocortex(superficial) and deep temporal lobe structures (hippocampus) -
Hypothalamus
- Mediodorsal thalamic nucleus
9
Q
Afferent fibers to anterior cingulate gyrus come from which 3 places:
A
- Anterior thalamic nucleus
- Dopaminergic fibers from ventral tegmental area
- Diagonal band of Broca
10
Q
Efferent fibers from anterior cingulate gyrus come from which 2 places?
A
Mediodorsal thalamic nucleus
- Subiculum
11
Q
What are the 2 major thalamic nuclei that play a role in the limbic system (relay links)?
A
anterior thalamic nuclei
mediodorsal thalamic nuclei
12
Q
What are the 3 main funcitons of the prefrontal cortex?
A
Cognitive processes
- Autonomic processes
- Emotional processes, including control over aggression and rage
13
Q
Damage to the prefrontal cortex can cause?
A
flat affect; loss of control of cognitive, autonomic, and emotional processes; memory and intellectual deficits
14
Q
What are the 3 main functions of the cingulate gyrus?
A
- Processing of visual and somatic sensations
- Cognitive
- Regulation of visceral (autonomic) processes by exerting a general suppressive effect
15
Q
Damage to the cingulate gyrus may cause?
A
damage may cause flat affect,
lack of empathy,
autonomic dysfunction,
poor decision making
16
Q
What are the 3 main components of the parahimppocampal gyrus?
A
Entorhinal cortex (anterior)
- Parahippocampal cortex (posterior)
- Perirhinal cortex (lateral)
17
Q
The major afferent source to the hippocampal region from the parahippocampal gyrus is :
A
the Entorhinal cortex
18
Q
What part of brain is Involved in the formation of declarative memories and in spatial processing?
A
Parahippocampal Gyrus
19
Q
Damage to what structure correlates with a loss in the ability to form new memories and also leads to inability to recognize scenes although objects in the scene can still be recognized (damage to spatial processing)?
A
parahippocampal gyrus
20
Q
What 3 structures make up the hippocampal formation?
A
hippocampus
dentate gyrus
subiculum (subicular cortex)
21
Q
CA1 (Sommer’s sector)- pyramidal cells of the hippocampus are highly susceptible to , especially during periods of lobe epilepsy
A
anoxia; temporal
22
Q
What is the ridge of small granular cells forming the outer border of CA4 of the hippocampus - Thought to play a major role in episodic memory formation?
A
Dentate gyrus
23
Q
What is being described ?
Transitional region between entorhinal cortex and hippocampus
- Major output of hippocampus; not a simple relay but functions as a unique computational unit
A
Subiculum (subicular cortex)
24
Q
Entorhinal region is major afferent source projecting to the?
A
hippocampus
25
Afferent fibers to entorhinal include which 2 structures of brain?
Association cortex (frontal, parieto-occipital, and temporal)
- Cingulate gyrus
26
Other afferents to the hippocampal formation other than the entorhinal complex of the parahippocampal gyrus are what 3 major afferents:
**Monoamine projections from brainstem reticular formation**
- Ventral tegmental area (dopamine) - Raphe nuclei (serotonin) - Locus coeruleus (norepinephrine) -
**Contralateral hippocampus**
**- Cholinergic neurons from septal nuclei and diagonal band**
27
Major pathway from the hippocampal formation?
fornix
28
What are the 3 components of the fornix system and where do they go?
precommissural fornix- septal area
postcommissural fornix- diencephalon (thalamus and hypothalamus)
comissural component-terminates in contralateral hippocampus
29
What are the 2 other efferent pathways from hippocampal formation other than the fornix?
Neurons in **subiculum** also project to entorhinal cortex, cingulate cortex, and areas of prefrontal cortex
- **Entorhinal cortex** projects to amygdala and adjoining regions of temporal neocortex
30
What does the anterior commissure connect?
temporal lobes
31
The significance of what projections are that they enable the hippocampal formation to communicate with widespread regions of neocortex and Serve to provide affective (emotional) properties to various modalities of sensory signals (like emotions associated with smell)?
subiculum and entorhinal cortex of the hippocampal formation
32
What brain formation functions to:
Certain forms of learning and memory
Differentially modulates aggressive behavior
Modulates endocrine functions
hippocampal formation
33
What 4 certain forms of learning and memory are the function of the hippocampal formation?
Spatial learning (spatial memory)
- Short-term memory
- Consolidation of memory (transferring short-term to long-term)
- Receives, processes, and categorizes sensory information during learning
34
How does the hippocampal formation modulate aggressive behavior?
Activation of hf **closest to amygdala** facilitates predatory attack behavior
- Activation of hf **closest to septal pole** suppresses this form of aggression
35
How and what part of the hippocampal formation modulates endocrine functions?
Ventral subiculum regulates the **hypothalamic-pituitary-adrenal axis**
36
What part of the thalamus is a reciprocal connection with the mammilary body of the hypothalamus and the cingulate gyrus?
anterior nucleus with thalamus
37
The septal area (ventral septum, diagonal band)
Amygdala/pyriform cortex
and
prefrontal cortex and anterior cingulate gyrus
are all inputs to which thalamic nuclei?
mediodorsal thalamic nucleus
38
Which specific hippocampal region is highly susceptible to anoxia, particularly during periods of temporal lobe epilepsy?
CA1 (Sommer’s sector)- pyramidal cells are highly susceptible to anoxia, especially during periods of temporal lobe epilepsy
39
What region of the brain provides the major input to the hippocampus?
entorhinal region
40
Identify the 3 specific components of the fornix system and the brain regions to which they connect the hippocampus.
41
What are the 3 main functions of the hippocampal formation?
Certain forms of learning and memory
Differentially modulates aggressive behavior
Modulates endocrine functions
42
How does activation of different areas of the hippocampus modulate aggressive behavior?
Activation of hf closest to amygdala facilitates predatory attack behavior
Activation of hf closest to septal pole suppresses this form of aggression
43
Which specific component of the hippocampal formation regulates the hypothalamic-pituitary-adrenal axis?
Ventral subiculum
44
What 2 thalamic nuclei are important in limbic pathways and what are their connections to other brain regions?
anterior thalamic nuclei reciprocal input/output from mamillary bodies of hypothalamus and cingulate gyrus
and
(view diagram concerning mediodorsal thalamic nuclei)
45
Name the major parts of this diagram?
46
Papex circuit (neuronal circuit)
Hippocampus → → mammillary body → mammillothalamic tract →
thalamic nuclei → thalamocingular tract → gyrus → cingulohippocampal fibers → hippocampus
Hippocampus → fornix → mammillary body → mammillothalamic tract → anterior thalamic nuclei → thalamocingular tract → cingulate gyrus → cingulohippocampal fibers → hippocampus
NOTE: start with the red pathway and end with green
47
What establishes a connection between information stored in the unconscious and conscious behavior?
Neuronal Circuit (Papez Circuit)
48
There **is/is not** a dorsal septal area in humans?
is not
(only septum pellucidum, which is devoid of nerve cells)
49
**Septal area afferent connections**
Medialstria
- Monoaminergic systems of -
Hippocampal formation
-
- Feedback signals from lateral hypothalamus
Medial olfactory stria
- Monoaminergic systems of brainstem
- Hippocampal formation
- Amygdala
- Feedback signals from lateral hypothalamus
50
What are the 2 main efferent connections of the septal area?
**Lateral septal** area projects to **hypothalamus -**
**Nuclei of diagonal band of Broca** have widespread connections with **other parts of limbic system** (parallels projection pattern of subicular cortex)
51
What is the main function of the septal area?
Relay and feedback system for hippocampal formation to hypothalamus;
52
What area of brain is implicated in aggression, rage, autonomic functions, and drinking behavior
Septal area
53
Septal area also has effects on endocrine system via
modulatory; hypothalamic-pituitary axis
54
Stimulation of septal area **facilitate/suppresses** ACTH secretion and adrenal activity
- Lesions of septal area **facilitate/suppress** ACTH release
suppresses
facilitate
55
Lesions of septal area can cause “ rage,” which refers to sudden outbursts of aggressive behavior
sham
56
What are the basal forebrain nuclei related to the limbic system?
Bed nucleus of stria terminalis
Nucleus accumbens
Substantia innominate (basal nucleus of Meynart)
57
What is the major efferent pathway from the amygdala?
stria terminalis
58
What is the function of the basal forebrain bed nucleus of the stria terminalis?
helps regulate autonomic and affective (emotional) processes
59
Which basal nuclei
Receives fibers from amygdala -
Projects to hypothalamus and midbrain PAG -
Believed to regulate autonomic, endocrine, and affective processes
Bed nucleus of stria terminalis
60
Which basal forebrain nuclei related to the limbic system:
Receives dopaminergic projections from brainstem
- Receives other inputs from amygdala and hippocampal formation
- Projects to substantia innominate, substantia nigra, and ventral tegmental area -
Believed to integrate motor (basal nuclei) and motivational (limbic system) processes
nucleus accumbens
61
Pathway from nucleus accumbens to has been implicated as **substrate** for addictive processes
ventral tegmental area
62
Which basal forebrain nuclei related to the limbic system is described:
Includes basal nucleus of Meynart - contains cholinergic cells that project widely to cerebral cortex and limbic structures (damage to this area is suggested in the etiology of Alzheimer disease)
- Shares reciprocal connections with amygdala
- Projects axons to lateral hypothalamus so it may also serve as a relay of signals from the amygdala to the lateral hypothalamus
substantia innominate
63
What are the 3 cortical areas that comprise the parahippocampal gyrus?
Entorhinal cortex (anterior)
- Parahippocampal cortex (posterior)
- Perirhinal cortex (lateral)
64
What are the consequences of damage to the parahippocampal gyrus?
Damage to this structure correlates with a loss in the ability to form new memories -
Damage also leads to inability to recognize scenes although objects in the scene can still be recognized (damage to spatial processing)
65
Be able to correctly sequence the structures that comprise the Papez circuit.
Hippocampus → fornix → mammillary body → mammillothalamic tract → anterior thalamic nuclei → thalamocingular tract → cingulate gyrus → cingulohippocampal fibers → hippocampus
66
What are the main functions of the septal area nuclei?
Relay and feedback system for hippocampal formation to hypothalamus
Septal area also has modulatory effects on endocrine system via hypothalamic-pituitary axis
67
What is believed to be the function of the bed nucleus of stria terminalis?
Believed to regulate autonomic, endocrine, and affective processes
68
What is the role of the nucleus accumbens in the limbic system?
Receives dopaminergic projections from brainstem
- Receives other inputs from amygdala and hippocampal formation
- Projects to substantia innominate, substantia nigra, and ventral tegmental area -
Believed to **integrate motor (basal nuclei) and motivational (limbic system) processes**
Pathway from nucleus accumbens to ventral tegmental area has been implicated as substrate for addictive processes
69
. What are the connections of the substantia innominate to other limbic structures?
contains cholinergic cells that project widely to cerebral cortex and limbic structures (damage to this area is suggested in the etiology of Alzheimer disease)
Shares **reciprocal connections with amygdala**
Projects axons to lateral hypothalamus so it may also serve as a relay of signals from the amygdala to the lateral hypothalamus
70
Which structure is located deep to the uncus and anterior to the tail of the caudate nucleus and is composed of nuclei?
amygdala
71
Major nuclear groups of the amygdala can be divided into which 2 components:
**Corticomedial group**
- Cortical nucleus - Basal nucleus, medial part
**Basolateral group**
- Central nucleus\* - Lateral nucleus - Basal nucleus, lateral part
72
What is the ultimate function of the central nucleus of the amygdala as the info passes to the hypothalamus and reticular formation?
regulatio of visceral responses to stimuli
73
What is the ultimate function of the corticomedial nucleus of the amydala as the information is relayed to the hypothalamus, reticular formation, and olfactory system?
emotional affective response to smell and food
74
What is the ultimate function of the basal lateral nuclei as the information passes to the association cortices and limbic cortex?
attaching emotional significance to stimuli
75
What are the 2 efferent pathways of the amygdala?
1. stria terminalis
2. ventral amygdalofugal pathway
76
which amydala pathway is described:
- Small tract arising primarily from **medial nuclei** -
Terminates in hypothalamus, ventral striatum, and septal nuclei
77
Which efferent pathway of the amygdala is being described:
Major efferent pathway arising from basolateral and central nuclei
- Terminates in hypothalamus, ventral striatum, septal nuclei, limbic cerebral cortical areas, and PAG
Ventral amygdalofugal pathway
78
What part of the brain Exerts most potent control over visceral processes of hypothalamus?
amygdala
79
Which part of the limbic system differentially modulates aggressive behavior, feeding and drinking behavior, and endocrine functions?
amygdala
80
amygdala plays a crucial response to stressors, such as fearful stimuli and stressful stimuli
Central
81
What role does the corticomedial nuclei of the amygdala as concerning aggressive behavior?
Stimulation- powerful, facilitating effect on defensive rage behavior
82
What role does the corticomedial nuclei of the amygdala play as concerning feeding and drinking behavior?
Inhibitory effect
83
What role does the corticomedial nuclei of the amygdala play as concerning ovulation?
Stimulation induces ovulation
84
What role does the corticomedial nuclei of the amygdala play as concerning growth hormone?
Stimulation- inhibits GH release
85
What role does the corticomedial nuclei of the amygdala play as concerning ACTH release?
Stimulation- inhibits release of ACTH
86
What role does the basolateral nuclei of the amygdala play as concerning ACTH release?
Stimulation- facilitates release of ACTH
87
What role does the basolateral nuclei of the amygdala play as concerning growth hormone?
Stimulation- facilitates release of GH
88
What role does the basolateral nuclei of the amygdala play as concerning ovulation?
no role, except Transection of stria terminalis abolishes ovulation
89
What role does the basolateral nuclei of the amygdala play as concerning feeding and drinking behavior?
facilitative effect
90
What role does the basolateral nuclei of the amygdala play as concerning aggressive behavior?
Stimulation- produces **opposite effect** of - powerful, facilitating effect on defensive rage behavior
91
Which disease process is described below?
Hypersexuality - Excessive eating (hyperphagia) - Decrease in anxiety toward fear-producing objects - Tendency to orally explore non-food objects (hyperorality) - Visual agnosia (can see but cannot recognize or interpret visual information) - Excessive attentiveness to visual stimuli with a tendency to touch every stimulus (hypermetamorphosis)
Kluver-Bucy syndrome
92
Which psychiatric disorder is associated with:
Limbic system, frontal lobe, basal nuclei Dopamine (excess)
schizophrenia
93
Which psychiatric disorder is associated with all of the follwing:
Orbitofrontal cortex, basal nuclei (especially head of caudate), anterior cingulate gyrus Serotonin (decrease)
obsessive-compulsive disorder
94
Which psychiatric disorder is being described:
Functional imaging studies show inconsistent results
Increase in noradrenaline and serotonin
anxiety
95
Which psychiatric disorder is most associated with:
Cerebral cortex (especially prefrontal cortex),
hippocampus Neuroendocrine changes: increased cortisol, decreased brain-derived neurotrophic factor (BDNF) and vascular endothelial growth factor (VEGF)
depression
96
What is the syndrome caused by amygdala ablation?
Kluver Bucy syndrome
97
What structures provide input to the amygdala?
thalamus, hypothalamus, hippocampus, prefrontal cortex, brainstem, olfactory system, sensory info
98
What are the 2 major efferent pathways of the amygdala?
stria terminalis, ventral amydalofugal pathway
99
What are the 2 main thalamic nuclei involved in the basal nuclei connections to the limbic system?
100
