Limbic System Flashcards
What are the functions of Limbic system?
- Emotional behavior related to survival. Visceral responses accompanying emotions.
- Process of turning short term memory into long term (consolidation)
-Limbic lobe
-Subcortical nuclei
-Connecting pathways
These are part of what?
Limbic system
Subcallosal area, cingulate gyrus, parahippocampal gyrus,
hippocampus and dentate gyrus. These are all part of what?
Limbic Lobe
Amygdala, septal, hypothalamus (e.g., mamillary bodies), thalamus
(e.g., anterior, mediodorsal), habenula, midbrain reticular formation. These are part of what?
Subcortical Nuclei
_____ gyrus:
-Junctional region between neocortex, and allo/archicortex
Parahippocampal gyrus
Entorhinal area is located within _____ gyrus.
Parahippocampal gyrus
Parahippocampal gyrus: Entorhinal area faces _____ and faces _____ formation.
Neorcortex; hippocampal
How many layers are in neocortex, and alloarchicortex?
3; 6
What structures are found within the Hippocampal formation? (3)
Hippocampus, Dentate gyrus, Subiculum
Hippocampal formation: How many layers does hippocampus (archicortex) have?
3 layers
Hippocampal formation: How many layers does Dentate gyrus have?
3 layers
Hippocampal formation: What is the Subiculum?
Transitional zone
Hippocampal formation: What are the 3 layers of Hippocampus?
Polymorphic cell (1 layer), Pyramidal cell,(Main type; 5) and Molecular layer(6).
Major input is from _____ cortex which receives input from all association cortices and projects back to those association areas
entorhinal cortex
_____ cells are among the first to to be affected in diseases resulting in memory loss and loss of intellectual functions.
Pyramidal cells (Main cell of hippocampus)
Neurogenesis: neuronal stem cells located deep to _____ cell layer; mature into _____ neurons; increase in ______ activity seen in response to appropriate sensory stimulation
granule; functional; mitotic
Entorhinal cortex is afferent or efferent of the fornix?
Both
What is the function of Entorhinal cortex?
Cognitive and sensory information from association cortices
Each one fornix (per side) has what 3 parts?
Crura, Body, and Columns
_____ Circuit: may be involved with cognitive processes including _____ functions which are processed through hippocampal formation via cingulate gyrus
Papez; memory
Cingulate gyrus> _____ area> Hippocampal formation> _____> Mammillary body> _____ Nucleus and Internal capsule> Cingulate gyrus
Entorhinal; Fornix; Anterior thalamic
What type of memory is stored in the Hippocampus formation?
Newly, short term memory
Limbic system has retention of information in _____ memory and its transfer into long term declarative memory
short term
_____potentiation is vital for consolidation of memory traces
Long-term
Cholinergic activity: significant for _____ [central ACh blockade severely impairs memory for lists of names, numbers]
learning
Is ACh made in the limbic system?
No, it is released here
What is Anterograde amnesia?
Loss of ability to create new memory, or recall of newly acquired information.
Bilateral damage or removal of anterior part of temporal lobe can cause what?
Anterograde amnesia
Bilateral damage or removal of anterior part of temporal lobe causes loss of _____ memory, not _____ memory.
Declarative; procedural (motor skill)
Lesion in mamillary bodies, thalamus and alcoholism can cause what syndrome?
Korsakoff’s
Loss of short term memory and fabrication of recent events is a symptom of what syndrome?
Korsakoff’s
Projections from basal cholinergic forebrain nuclei (ACh) lost and/or degenerative changes in entorhinal area and hippocampus. Can cause what disease?
Alzheimer’s (memory loss)
Amygdaloid body: Group of nuclei in the dorsomedial portion of the _____ lobe, near
the tip of the _____ horn.
temporal; inferior
Limbic and amygdaloid body are essential for?
Survival
Emotions = activities of the brain evoked by incentives for survival; fear (evaluates “threat”; is a behavioral response appropriate for each situation). What is it?
Amygdaloid body
What are the 3 nuclei of Amygdala?
Basolateral (largest), Central, and Corticomedial (poorly developed)
What are the 3 subcortical afferents to amygdala?
Thalamus; RF; Hypothalamus
Cortical afferents to amygdala: All association areas which are also linked with _____ cortex
prefrontal
Amygdaloid has reciprocal between _____ and _____ neocortices and anterior cingulate gyrus.
prefrontal; temporal
Efferent of Amygdaloid: Stria terminalis projects to?
- Septal area(indirectly influences autonomic nuclei)
- Preoptic area
- Anterior hypothalamus
Efferent of Amygdaloid: Ventral amygdalofugal projects to?
- Mediodorsal thalamic nucleus> Prefrontal cortex*
- Nucleus accumbens
Amygdaloid is involved with the behavioral and emotional functions of the limbic system. What are they? (4Fs)
Fight, Fleeting, Feeding, F***
Nuclei of Amygdala: Corticomedial (poorly developed) function?
Respond to unpleasant/ pleasant odors
Nuclei of Amygdala: Basolateral (largest) function?
Assess nature of input (threat or not) ; provides perception of emotion
Nuclei of Amygdala: Central function?
Along with Corticomedial: Appropriate autonomic and motor responses (expression of emotions)
Nature of input: friendly (or not), frightening, dangerous. Which Amygdaloid nuclei assesses?
Basolateral
Dorsal longitudinal fasciculus and Medial forebrain bundle are both part of what system?
Limbic system
Amygdala activity produces the _____ and _____ responses that accompany fear and anxiety
autonomic; somatic
A lesion in Amygdala or bilateral removal of the temporal lobes (including amygdala and much of the hippocampus) will cause what syndrome?
Kluver-Bucy syndrome
What are the symptoms of Kluver-Bucy syndrome?
–Absence of _____ responses
– Overly attentive to all _____ stimuli; examine all objects visually, tactilely, and orally
– _____ (may be perverse)
– Visual agnosia (objects are not
recognized visually- damage to posterior _____ lobe)
emotional; sensory; Hypersexuality; temporal
Anxiety and phobias, Schizophrenia, Epilepsy can all be linked to _____ dysfunction.
Amygdala
-Activity of visual association cortex via hippocampus to
amygdala leading to inappropriate activity and excessive symptoms of anxiety
-Fearful visual images may be recalled by the current visual scene.
These are symptoms of?
Anxiety and Phobias
Regionally specific atrophy predominantly affecting
medial temporal lobe, frontal and temporal parts of cortex, and thalamus. This is a symptom of?
Schizophrenia
Most frequent focal site is medial surface of temporal
lobe. This is symptom of?
Epilepsy
