L21 and 22 - A Flashcards
The Limbic System is a border that separates which two structures?
Neocortex and Diencephalon
Which seven structures belong to the Limbic System?
- Hippocampal formation
- Amygdala
- Septal Nuclei
- Cingulate Cortex
- Entorhinal Cortex
- Perirhinal Cortex
- Parahippocampal Cortex
True or False: The hippocampus is also known as the cornu ammonis (Ammon’s Horn)
True
Which three components make up the Hippocampal Formation–which is a curved and re-curved sheet of cortex folded into medial surface of temporal lobe?
- Hippocampus proper
- Dentate Gyrus
- Subiculum
Which two structures form two interlocking “C’s”
A. Hippocampus proper
B. Dentate Gyrus
C. Subiculum
A. Hippocampus proper
B. Dentate Gyrus
The hippocampus (and dentate gyrus) is actually a cortex, but it is a __ layered cortex as opposed to the __ layered cortex as in the neocortex
3; 6
Because of the small number of layers and their location between the neocortex and diencephalon, these cortices have been called ____
paleocortex
True or False: The hippocampus and the dentate gyrus, like the neocortex, have both a DEEP and SUPERFICIAL “molecular” layer
True
- note: molecular layer (inside) and polymorphic layer (outside)
What is the middle layer of the hippocampus proper known as?
What is the middle layer of the dentate gyrus known as?
pyramidal cell layer
granular layer
Inner layer of hippo - ________
Middle layer -________
Outer later - __________
Inner = molecular
Middle = pyramidal (hippo) / granule (dentate gyrus)
Outer = polymorphic
True or False: The molecular layer of the hippocampus proper faces the dentate gyrus
True
____: Area of the hippocampus proper that is capped by the dentate gyrus
A. CA3
B. CA2
C. BCB1
D. Alveus
A. CA3
_____: Polymorphic layer of the hippocampus; it is equivalent to the white matter of the neocortex
A. CA3
B. CA2
C. BCB1
D. Alveus
D. Alveus
True or False: The subiculum is the transition layer from the hippocampus to the parahippocampal gyrus (also - it changes from 3 to 6 layers)
True
A major flow of information through the hippocampus comes from the….
A. PFC
B. Entorhinal Cortex
C. Primary Somatosensory Cortex
B. Entorhinal Cortex
True or False: Neural activity can modify synaptic strength in certain parts of hippocampus – modified synaptic strength may be storage mechanism for memory
True
True or False: Large, bilateral lesions of the hippocampus will affect memory of remote events and general intelligence; however, the person will be able to learn new facts and skills
False - large, bilateral lesions of the hippocampus will NOT affect memory of remote events and general intelligence; however, the person CANNOT learn new facts and skills
Why do patient’s with Korsakoff Syndrome have a hard time forming new memories?
Mammillary bodies are destroyed
What is the major pathway INTO and OUT of hippocampus?
A. PFC
B. Entorhinal Cortex
C. Primary Somatosensory Cortex
D. Fornix
D. Fornix
True or False: The fornix starts as the alveus, communicates bidirectionally, and has efferent/afferent fibers
True
____: White matter of the hippocampus, which consists of myelinated afferents/efferents
Alveus
Which two structures come together to form the hippocampal commissure?
Crura
The fornix continues to an arc to the ___ ___
anterior commisure
______: An important landmark, since this is where the fornix splints into three columns, going to different structures
A. Crura
B. Fornix
C. Anterior Commisure
C. Anterior Commisure
The split just before the anterior commisure is called the ______ while the split after the anterior commisure is called the ______
precommisual fornix; postcommisual fornix
Which two places does the postcommisural fornix branch lead to?
- Mammillary bodies (hypothalamus)
- Anterior nuclei (thalamus)
What are the two major pathways by which the hippocampi communicate with one another?
1) Hippocampal commissure
2) Anterior commisure to c/l hippocampus
Which three structures does the precommissural fornix go to?
1 - Septal nuclei
2 - Ventral striatum
3 - Cingulate cortex
_____: Integrative center for emotions, emotional behavior, and motivation
Amygdala
True or False: Both the hippocampus and amygdala have major pathways that communicate bilaterally and contain both efferent/afferent fibers
True
True or False: The amygdala receives inputs from all senses, as well as visceral inputs
True
Which four structures provide visceral inputs to the amygdala?
- Hypothalamus
- Orbital cortex
- Parabrachial nucleus
- Septal area
True or False: Olfactory sensory info goes from the olfactory bulb to the amygdala
True
Where does auditory, visual, and somatosensory info, which eventually reach the amygdala, come from?
Temporal and Anterior Cingulate Cortices
What are the major output pathways of the amygdala?
1) Ventral amygdalofugal
2) Stria terminalis
3) Directly to hippocampus
4) Directly to entorhinal cortex
5) Directly to thalamus
6) Brain stem connections
Projects from the ventral striatum links in a basal ganglia circuit that is important for what type of learning?
stimulus-response associative learning
The amygdala’s major connection to the hypothalamus and septal nucleus is through the ___ ____
stria terminalis
True or False: The stria terminalis is important because it acts as a link whereby motivations and drives can influence response / is a link where responses are learned (associative learning)
False - ventral amygdalofugal pathway is important because it acts as a link whereby motivations and drives can influence response / is a link where responses are learned (associative learning)
True or False: Stimulation of amygdala causes intense emotions (e.g fear, aggression) while destructive lesions – as in Urbach-Wiethe–cause flat affect (humans)
True
How does the Stria terminalis connect to subcortical structuers?
Via: ventral amygdalofugal pathway
True or False: Both hippocampi and amygdala communicate with one another via: anterior commisure
True
True or False: The hypothalamus is a principal center of emotional expression and depends on both parasympathetic and sympathetic components of autonomic nervous system
True
When we experience feelings/emotions only subjectively, this is related to the ___ ____
A. Amygdala
B. Cerebral Cortex
C. Hippocampus
B. Cerebral Cortex
Emotional reactions or physical expression of emotion are more objective and are mediated through ______ connections
A. Amygdala
B. Cerebral Cortex
C. Hippocampus
D. Hypothalamic-autonomic connections
D. Hypothalamic-autonomic connections
____ region plays an important role in regulating release of gonadotrophic hormones from the anterior lobe of the pituitary
A. Cerebral Cortex
B. Preoptic
C. Hippocampal
B. Preoptic
True or False: In females, gonadotrophic hormones are released in a cyclical manner whereas, in males, the release is topical, with regular fluctuations
True
True or False: The ventromedial nucleus is important in male typical behaviors (e.g mounting) while the Preoptic are is important in female typical behaviors (e.g lordosis)
False - preoptic = male typical / VMN = female typical
True or False: The sexually dimorphic nucleus (pre-optic area) is large in male rats vs. females
True
True or False: INAH-3 is smaller in homosexual men, similar in size to heterosexual females
True
True or False: Homosexual men have anterior commisure that were 34% larger than those of heterosexual males and 18% larger than heterosexual females
True
True or False: Suprachiasmatic nucleus is smaller in homosexual vs. heterosexual males
False - it is larger
Stimulation of the lateral part of the anterior ____ evokes flight responses
A. Amygdala
B. Hippocampus
C. Hypothalamus
C. Hypothalamus
Intense stimulation of VM nucleus induces ___, ___
hissing, snarling
Stimulation of preoptic area evokes ___ sensation while VM stimulation produces ____ reaction
pleasurable; avoidance
______: Contains circadian pacemaker cells, generates endogenous rhythms (influenced by light stimuli) considered to be “master clock”
Suprachiasmic nucleus
True or False: The Septum includes both cortical tissue + subcortical nuclei
True
Which two pathways can afferents take to reach the septal nuclei?
1) Hippocampal formation - via fornix
2) Amygdala - via: stra terminals
Which two pathways can efferents take to reach the septal nuclei?
1) Lateral hypothalamus/midbrain segmentum via medial forebrain bundle
2) Hippocampus via fornix
___ ___ function as pleasure center
Septal nuclei
