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34 Cards in this Set
- Front
- Back
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What is the limbic system?
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a group of inter-connected brain
regions consisting of cortical and sub-cortical structures within the basal forebrain and “limbic” aka cingulate cortex |
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What is the limbic system's main functions?
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emotion, motivation and cognition
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The limbic system includes...
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-Cingulate cortex and PFC (thinking)
-Hypothalamus (homeostasis; drive) -Thalamus (sensory relay) -Amygdala (learning and fear) -Hippocampus (learning and memory) -Nucleus Accumbens (reward; drive) |
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Where is the thalamus located?
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diencephalon
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What is the thalamus involved in?
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-initial processing of all sensory information (except smell) prior to
information processing by primary sensory cortex (incl. vision and hearing); -the thalamus also processes motor information prior to communicating with the primary motor cortex |
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What is the amygdala involved in?
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perception of emotion and is reactive to emotional contexts (particularly fear)
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The amygdala is a very small structure, but contains...
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several nuclei that play different roles in emotional responding
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The amygdala receives sensory input from...
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all modalities
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The amygdala communicates...
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to the thalamus, as well as sends diffuse (spread out) projections to other members of the limbic system
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The amygdala receives sensory information from the...
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somatosensory cortex, sensory input from the thalamus and DIRECT input from the olfactory nerve (one of our cranial nerves)
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Besides sensory input, one of the
major inputs to the amygdala is the... |
hippocampus(memory)
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The amygdala sends projections
to the... |
-hypothalamus (stress, hunger, etc
responses) and to the hindbrain nuclei involved in controlling ANS function (e.g. arousal and cardivascular….) -Also projections to ventral striatum (aka nucleus accumbens) links to “limbic-motor interface |
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What are the 3 major nuclei of the amygdala?
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Medial Nucleus, Lateral/basolateral Nucleus, Central Nucleus
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What does the medial nucleus do?
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-receives olfactory information (odors; phermones)
-sends excitatory signals to hypothalamus ->drive/motivation |
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What doe the Lateral/basolateral Nucleus do?
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-receives sensory information & information about memories (hippocampus)
-sends excitatory signals to the nucleus accumbens (a.k.a ventral striatum -> (reward/motor region) |
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What does the Central Nucleus do?
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-receives information from lateral & basolateral nucleus of the amygdala
-sends excitatory signals to a host of regions involved in arousal (hypothalamus, midbrain structures, pons and medulla) ->arousal/drive/motivation |
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The neurochemical output of the amygdala is primarily excitatory (going to generate action potentials)....
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glutamate!
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What is the critical site for fear-associated emotion?
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central nucleus of the amygdala
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Stimulation of the Central Nucleus of the amygdala produces...
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fear-like response:
-freezing and shivering -sympathetic and neuroendocrine system activation (piloerection, Epi, NorEpi and cortisol secretion, increased heart rate, blood pressure etc) |
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What happens if there is damage to the central nucleus?
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obliterates fear response
-Approach dangerous situations, do not detect/remember a site, sound or smell as fearful, no autonomic nervous system activation |
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What is a conditioned fear response?
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learning about fearful situations
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Lesioning the LH inputs from the Central Nucleus...
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prevents fear conditioning ->amygdalar signaling to hypothalamus is also important for fear learning
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What is the critical site for conditioned
(learned) reward? |
basolateral nucleus of the amygdala
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Altered PFC activity and enhanced amygdala activity is associated with...
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depression!
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The hippocampus is highly involved in...
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the transition of information from short-term memory to long-term memory (consolidation)
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Where is the hippocampus located?
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Looped structure (named for sea-horse shape) that extends from the cingulate cortex to the amygdala and is located mostly in the temporal lobes
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What is anterograde amnesia?
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the inability to recall new events, people, places and things
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What is Korsakoff’s syndrome?
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the result of brain damage that produces anterograde amnesia and is usually the result of chronic alcoholism
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Hippocampus damage and disorganization has also been associated with...
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schizophrenia
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The hippocampus is a region that
has.... |
new neurons incorporating into its circuitry during adulthood.
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Neurogenesis in adult brain has
been linked to the existence of... |
neural stem cells which hold tremendous potential for treating
neurodegeneration. |
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Hippocampus sends neurons to...
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hypothalamus
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Hippocampal activation by stressful
memories can stimulate... |
the PVN to initiate the HPA cascade
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Recurrent stressful memories
(depression) can produce... |
a hyperactivity of the HPA axis and all the associated health problems, including cell death!!!!
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