Neuroscience Week 6: Limbic System Flashcards
(102 cards)
1
Q
Limbic System Functions
A
has a role in basic emotions such as anger and fear and is the part of the brain that regulates basic “fight or flight” behaviors
- Homeostasis
- Olfaction
- Memories
- Emotions
- Reward pathway
2
Q
Limbic system Mnemonics
A
HOMER
- Homeostasis
- Olfaction
- Memories
- Emotions
- Reward Pathway
5Fs
- Feeling
- Feeding
- Fleeing
- Fighting
- Fucking
3
Q
Limbic system was first described by?
A
Paul Broca in 1870’s
4
Q
Identify Limbic System
A
5
Q
limbus definition
A
medial border of the brain between the upper border of the cortex and the brainstem
6
Q
Describe Limbic circuitry
A
7
Q
Emotions have what components?
A
Emotions have significant visceral and autonomic components
8
Q
Which cortical areas have direct connection with the hypothalamus?
A
- Most cortical areas have no direct connections with the hypothalamus.
- Limbic-cortical areas and limbic areas connect directly to the hypothalamus
9
Q
Hypothalamus Nuclei
7 listed
A
- Lateral Nucleus
- Ventromedial Nucleus
- Anterior Nucleus
- Posterior Nucleus
- Suprachiasmatic Nucleus
- Supraoptic/Paraventricular Nucleus
- Preoptic Nucleus
10
Q
Hypothalamus: Lateral nucleus function
A
Feeding behavior
11
Q
Hypothalamus: Lateral nucleus stimulated by?
A
Stimulated by Ghrelin
12
Q
Hypothalamus: Lateral nucleus inhibited by?
A
Inhibited by Leptin
13
Q
Hypothalamus: Lateral nucleus Damage leads to?
A
failure to thrive/anorexia
14
Q
Hypothalamus: Ventromedial nucleus function
A
Satiety
15
Q
Hypothalamus: Ventromedial nucleus Stimulated by?
A
Leptin
16
Q
Hypothalamus: Ventromedial nucleus Damage leads to?
A
Hyperphagia
17
Q
Hypothalamus: Anterior nucleus function
A
Cooling
18
Q
Hypothalamus: Anterior nucleus Controlled by?
A
Parasympathetic/Sympathetic Control
19
Q
Hypothalamus: Posterior nucleus function
A
heating
20
Q
Hypothalamus: Posterior nucleus controlled by?
A
Sympathetic control
21
Q
Hypothalamus: Suprachiasmatic nucleus function
A
Circadian rhythm
22
Q
Hypothalamus: Suprachiasmatic nucleus regulation
A
control of sleep and wake cycles
23
Q
Hypothalamus: Supraoptic/Paraventricular nucleus function
A
Synthesize ADH and oxytocin
24
Q
Hypothalamus: Supraoptic/Paraventricular nucleus Regulation
A
ADH and Oxytocin are carried to posterior pituitary for storage and release
25
Hypothalamus: Preoptic nucleus Function
Thermoregulation & sexual behavior (Release GnRH)
26
Hypothalamus: Preoptic nucleus malfunction
Failure of GnRH neurons to migrate leads to Kallmann Syndrome
27
Hypothalamus homeostatic regulatory functions
7 listed
**TAN HATS**
* **T**hirst and water balance
* **A**denohypophosis (anterior pituitary)
* **N**eurohypophosis (posterior pituitary)
* **H**unger
* **A**utonomic nervous system
* **T**emperature
* **S**exual urges
28
Identify Limbic system and which are components of each pathway
* Medial Limbic Circuit (Papez) yellow
* Limbic Loop (Reward Pathway) Red
29
Papez circuit AKA
Medial Limbic Circuit
30
Medial Limbic Circuit AKA
Papez Circuit
31
Medial Limbic Circuit primarily involved in?
Memory formation and propagation of epileptic seizures
32
Medial Limbic Circuit path from the hippocampus
hippocampus→(up through fornix)→Mamillary bodies→(project up)→anterior nucleus of the thalamus→(thalamic projections up)→cingulate gyrus←input from mid-orbitofrontal cortex and lateral prefrontal cortex
Cingulate gyrus→(project down through entorhinal cortex to the temporal lobe back to the)→hippocampus
33
Components of the Medial Limbic Circuit
4 listed
* Hippocampus
* Mammillary bodies
* anterior thalamic nuclei
* Cingulate gyrus
34
Medial Limbic Circuit Pathway from the Hippocampus
* hippocampus→(up through fornix)→
* Mamillary bodies→(project up)→
* anterior nucleus of the thalamus→(thalamic projections up)→
* cingulate gyrus
* ←input from mid-orbitofrontal cortex and lateral prefrontal cortex
* Cingulate gyrus→(project down through entorhinal cortex to the temporal lobe back to the)→
* hippocampus
35
The Medial Limbic Circuit is important in?
The MLC is important in learning, memory and mesial temporal epilepsy
36
Limbic circuit related to mesial temporal epilepsy?
Medial Limbic Circuit
37
Medial Limbic Circuit Mnemonic
He-Man Ate a Cat
He = Hippocampus (limbic system)
Man = Mammillary body (hypothalamus)
Ate -= Anterior thalamic Nuclei (thalamus)
Cat = Cingulate gyrus (limbic system)
38
Hippocampus location
the hippocampal formation is easily seen on the ventro-medial aspect of the temporal lobe and comprises the floor and medial wall of the inferior horn of the lateral ventrical
39
Entorhinal cortex is the _______ pathway
Input pathway
40
Identify components
41
Dentate gyrus receives input from
Entorhinal cortex
42
Dentate gyrus projects to?
mossy fibers (axons of neurons from the dentate gyrus) project to CA3
43
CA3 Projects to?
CA2
44
CA2 projects to
CA1
45
CA1 projects to
back to the subiculum
46
synapses on CA2, CA1 AKA
Schaeffer Collaterals
47
Where are new neurons made?
Neurogenesis occurs in the Dentate gyrus and nowhere else
48
Specific neurons from the subiculum form the
Fornix
49
Some subiculum neurons also project directly back to the?
Entorhinal cortex not just to the fornix
50
Fornix is comprised of?
axons from pyramidal neurons in the hippocampus and subiculum
51
The majority of axons in the fornix project to
the mammillary bodies of the hypothalamus
52
Damage to the mamillary bodies will lead to
memory impairments
53
Identify
fornix
54
hippocampal commissure and importance
* connects both hemispheres of the hippocampus
* need bilateral damage to have anterograde amnesia (inability to form new memories)
55
Anterograde amnesia Definition
inability to form new memories
56
Anterograde amnesia causes
bilateral damage to the hippocampus because of the hippocampal commissure
57
Hippocampus connection to cortical areas
* memories are not formed in isolation, they have sights, smells, sounds and what's going on
* constant frontal monitoring attention appropriately
58
The limbic loop AKA ________ pathway
Motivation pathway
or
reward pathway
59
The limbic loop uses this(ese) neurotransmitters? from?
dopamine from the ventral tegmental area
60
The limbic loop: nucleus accumbens gets input from
2 listed
* Medial PFC
* Limbic prefrontal cortex
61
Nucleus accumbens projects to?
ventral pallidum
62
Nucleus accumbens is located in the?
Ventral Striatum
63
All drugs of abuse and stress affect the activity of this nucleus
Nucleus Accumbens
64
Cortico-striatal loops and behavior
65
Limbic loop distinguished from the motor loop by?
4 listed
* the source and nature of the cortical input (orbital and medial prefrontal)
* The division of the striatum and pallidum that process the input (both are in the ventral areas)
* The source of dopaminergic neurons from the midbrain (VTA)
* the thalamic target of the pallidal output (MDT)
66
Amygdala location
the amygdala is the other major limbic structure of the temporal lobes, lying directly in front of the hippocampus
67
The amygdala and the prefrontal cortex are involved in?
The formation of fears and phobias
68
CNS components involved in the formation of fears and phobias
amygdala and prefrontal cortex
69
Lesions of the amygdala result in?
5 listed
* decreased aggression "tameness"
* hypersexuality
* hyperorality
* visual agnosia
* lack of fear
70
Limbic components: Amygdala
71
most important Nuclei of the amygdala
* basal nucleus
* lateral nucleus
* or basolateral nucleus of the amygdala
72
Amygdala pathway
73
Damage to the bilateral amygdala leads to?
Inability to experience fear
However, greater than average fear and panic attacks in response to novel physiological fearful experiences such as feelings of suffocation
Kluver-Bucy Syndrome
74
Kluver-Bucy Syndrome
* The absence of emotional responses (fear, rage, aggression) (amygdala)
* Over-attention to sensory stimuli (amygdala)
* Hypersexuality (amygdala)
* Visual Agnosia (inability to recognize objects visually) (temporal cortex)
75
Visual Agnosia definition
Inability to recognize objects visually
| (temporal cortex)
76
Nucleus Accumbens Location
one of the septal nuclei in the ventral striatum
77
besides from the VTA the ________________ is a convergent site for input from the amygdala, hippocampus, entorhinal cortex and anterior cingulate gyrus
Nucleus Accumbens
78
The ________ has reciprocal connections to many of these areas but also projects to \_\_\_\_\_\_\_\_\_\_\_\_.
* Nucleus Accumbens
* The frontal cortex
79
\_\_\_\_\_\_\_\_\_, \_\_\_\_\_\_\_\_\_, \_\_\_\_\_\_\_\_, \_\_\_\_\_\_\_, and \_\_\_\_\_\_\_\_\_\_receive a significant dopaminergic innervation from the Ventral tegmental area (VTA) of the midbrain
5 listed
* Limbic cortical areas
* amygdala
* hippocampus
* septal nuclei
* Nucleus accumbens
80
\_\_\_\_\_\_\_\_\_ neurons in the septal and basal nuclei are important components of the \_\_\_\_\_\_\_\_\_
* Cholinergic neurons
* limbic system
81
Diagonal band of Broca
+
Nucleus Basalis of Meynert
location
82
Nucelus basalis of Meynert
83
Identify
84
Identify
85
Diagonal band of Broca
+
Nucleus Basalis of Meynert
and the limbic system
* cholinergic neurons in the septum and the basal forebrain project to the cortex and hippocampus and play an important role in modulating learning and memory systems
* these neurons degenerate at early stages of Alzheimer's Disease
86
Identify
87
The limbic loop and motivation
Association with depression
88
The limbic and olfactory systems
89
Prirform and pre-piriform cortex location
located in the uncus
90
The primary olfactory cortex is located in?
the uncus in the piriform and pre-piriform cortex
91
Identify
92
Identify
93
Seizure activity is common in the \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_.
Ventromedial temporal lobe (parahippocampal gyrus and uncus)
94
It is frequently associated with olfactory hallucinations (rotten-egg smell)
* seizure activity anventromedial temporal lobe (parahippocampal gyrus and uncus) (mesio temporal lobe epilepsy)
* it is thought that sense they are adjacent to the primary olfactory cortex it is stimulated
95
mesio temporal lobe epilepsy is associated with?
It is frequently associated with olfactory hallucinations (rotten-egg smell)
&
the medial Limbic circuit
96
Lying just deep to the uncus is the?
Amygdala
97
the primary olfactory cortex projects to the?
Entorhinal cortex and then to the orbitofrontal cortex for discriminating olfactory input
98
The ____________ projects to the Entorhinal cortex and then to the orbitofrontal cortex for discriminating olfactory input
Primary olfactory cortex
99
Summary
100
Nucleus Accumbens receives input from
4 listed
* hippocampus
* amygdala
* VTA (DA)
* Dorsal Raphe (5-HT)
101
Kallman Syndrome
Kallmann syndrome is a condition characterized by delayed or absent puberty and an impaired sense of smell. This disorder is a form of hypogonadotropic hypogonadism, which is a condition resulting from a lack of production of certain hormones that direct sexual development.
102
Damage to which area produces Kallman Syndrome
Preoptic nucleus of the hypothalamus
