Term
| what is the limbic system? |
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Definition
| an interrelated group of cortical/subcortical structures which are involved w/the regulation of the internal/emotional state and the accompanying physiological, behavioral, and psychological responses. |
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Term
| what structures are associated with the limbic system? |
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Definition
| the limbic cortex, the *amygdala, the *hippocampal formation, the *olfactory complex, the *septal area/basal forebrain, and the hypothalamus. |
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Term
| what functions are associated with the hypothalamus? |
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Definition
| autonomic function, emotion, endocrine function, homeostasis, motor function, regulation of food/water intake, and regulation of sleep/wake cycle |
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Term
| what is the cingulate gyrus, a part of the limbic cortex interconnected with? |
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Definition
| visual, auditory, and tactile-spatial input |
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Term
| where is the parahippocampal gyrus in relation to the limbic cortex? |
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Definition
| on the inferior side - which is where the uncus/amygdala is also located |
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Term
| what involvement does the insula cortex bring to the limbic system? |
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Definition
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Term
| what is the involvement of the olfactory nerve w/the limbic system? |
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Definition
| the olfactory bulb projects directly into the amygdala (limbic system) |
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Term
| what function does the amygdala perform? |
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Definition
| control of emotion. it is the "storehouse for the memory of fear" which provides sensory information w/affective value, communicates w/brain functions controlling effective function (motor function, autonomic response, release of hormones, etc), and responds to emotionally charged events in memory (which projection from prefrontal cortex can inhibit according to context) |
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Term
| what function does the hippocampus perform? |
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Definition
| learning/declarative memory. |
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Term
| what are the different zones in the hippocampus? |
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Definition
| 1) hippocampus proper (pyramidal cells). 2) dentate gyrus (granular cells). 3) subiculum. |
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Term
| where is one of the first places which signaling goes from the hippocampus (the end of which is the subiculum)? |
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Definition
| the entorhinal cortex, however the fornix/septal nuclei (pleasure center) is another common output from the hippocampus |
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Term
| what are the key fiber tracts associated w/the limbic system? |
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Definition
| fornix: conveys information from *hippocampus to septal nuclei and mammillary body (nuclei of hypothalamus) and stria terminalis which conveys information from amygdala to the septal area and hypothalamus. |
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Term
| what is papez's circuit (the more hippocampal portion of the limbic system)? |
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Definition
| cingulate gyrus -> hippocampus -> fornix -> mamillary bodies - > *mammillothalamic tract -> *anterior nucleus of dorsal thalamus (filter) -> cingulate gyrus...prefrontal cortex etc |
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Term
| what is the amydala's cycle in the limbic system? |
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Definition
| amygdala -> stria terminalis -> (the *ventral amygdalofugal pathway*) -> thalamus -> cerebral cortex -> amygdala... |
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Term
| what are the 2 types of long term memory? which of these is the hippocampus involved in? |
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Definition
| 1) declarative/explicit (hippocampus-associated): episodic (remembering events) and semantic (knowing facts). 2) non-declarative/implicit/procedural: skills/habits (basal ganglia, cerebellum, neocortex), emotional associations (amygdala), and conditioned reflexes (cerebellum). |
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Term
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Definition
| the process of storing new information in long-term memory where novel factual information is relayed from relevant areas to the hippocampal complex for encoding and memory becomes independent of the hippocampus. |
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Term
| what will result from lesions in the amygdala? |
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Definition
| inability to recognize emotional facial expressions |
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Term
| what will result from lesions in the prefrontal cortex? |
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Definition
| interruption of inhibitory amygdala control and disinhibition of emotional responses = socially inappropriate behavior and impulsivity |
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Term
| what will result from lesions in the hippocampus and medial temporal cortex? |
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Definition
| inability to learn new information (short term memory) and loss of declarative memory (facts) = amnesia |
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Term
| what will result from lesions in the lateral temporal lobe? |
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Definition
| inability to recall remote events or previously learned facts (long term memory) |
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Term
| what are classic diseases associated w/the limbic system? |
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Definition
| alzheimer's disease: loss of recent memory. korsakoff: loss of recent memory and *confabulation. kluver-bucy: behavioral changes. |
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Term
| what is alzheimer's disease? |
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Definition
| loss of neurons in the hippocampus/parahippocampus and formation of amyloid plaques = progressive loss of memory, cognition, orientation, and behavior. (advanced = loss of neurons in the frontal cortex progressing to the parietal cortex and reduction in cholinergic innervation of the cerebral cortex) |
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Term
| what is korsakoff's syndrome? |
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Definition
| damage to the hippocampus, mammillary bodies, and thalamus (alcoholism/vit B1 deficiency) - memory deficiency, inability to form new memories, and intact intelligence thus confabulates. |
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Term
| what is kluver-bucy syndrome? |
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Definition
| destruction of the amygdala = absence of emotional responses (fear, rage, aggression cease to exist), compulsion to be overly attentive to all sensory stimuli, hypersexuality, and psychic blindness/visual agnosia (objects are not recognized visually). |
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Term
| does neurogenesis occur in the brain? |
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Definition
| yes, though not fully. new neurons arise from "neural precursors". |
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