Limbic Flashcards
HOME
Homeostasis Olfactory Memory Emotion
Dentate gyrus
Internal part of the hippocampus
Fornix
Efferent of hippocampus to the mammillary body of the hypothalamus. The fornix travels above the thalamus
Mammilothalamic tract
Info from the hippocampus travels to the hypothalamus along the fornix. It then journeys from the hypothalamus to the thalamus via the mamillothalamic tract.
Stria terminalis
Connects the amygdala to the hypothalamus
Papez’s circuit
Hippocampus to the fornix to the mammillary bodies to the mammiloththalamic tract to the anterior thalamus to the cingulate gyrus ( through the internal capsule) to the cingulum ( this white matter tract) to the parahippocampus to teh entorrhinal cortex and finally to teh perforant pathway to thake you back to the hippocampus.
use of the entorrhinal cortex
Declarative memory as well as spatial memories and memory consolidation
Effect of herpes on limbic system
Severe behavioral and memory disturbances. Herpes virus has a specific affinity for the hippocampus
NT characteristic of papez circuit
The papez circuit is characterized by a high density of cholinergic innervation and opiate receptors which is how we link emotions to memory.
Uncal seizure
The entire limbic system can be implicated by uncal seizure that is preceded by a terrible smell
Perforant Path
Path from the Entorhinal cortex to the Dentate of the hippocampus
Providers of cholinergic input for the brain
Septal nuclei and nucleus basalis of Meynert provide cholinergic input for the brain (memory)
Mesocorticolimbic Dopamine system
critical for positive reinforcing brain mechanisms. (drugs and pleasure).
Outer core structures of the limbic system
These will be cortical in function. The orbital cortex, cingulate gyrus and the entorhinal cortex.
Damage to outer cortex of limbic system
Significant personality changes, disinhibition, impulsivity, shild-like behaviour
Entorrhinal cortex
Anterior part of the prahippocampal gyrus, associated with olfaction and memory
Outer core-cortical components
A) Cingulate cortex
-rostral-emotions and motor
-caudal-visual spatial memory
B) Orbital frontal lobe
- personality, behavior control and self awareness
c) Temporal lobe (hippocampus, parahippocampus, entorhinal cortex)
-memory
Hypothalamus
Pleasure center, autonomic, endocrine integration.
Neurons project to the pituitary, regulate ACTH and TSH secretion; involved in maternal behavior , blood pressure , feeding, temperature regulation and immune response
Amgydala
” preservation of self” behaviors, emotion, social behavior, aggression and defense response, sexual behavior, affective significane of visual stimuli, affect of faces, affective regulations
Septum
” preservation of species” behaviors, sexual behavior, emotionality
Medial forebrain bundle
Connects hypothalamic nuclei and amygdala and brainstem nuclei
Perforant path
Connection from the entorhinal cortex to the dentate gyrus of the hippocampus
Kluver-Bucy Syndrome
Agnosia= psychic blindness = cannot detect the meaning of objects base on visual criteria
Oral tendencies= examine all objects by mouth
Hypermetamorphosis= notice and react to every visual stinulus
Tameness = no motor or vocal reactions with fear or anger
Hypersexuality
Kluver-Bucy etiology
Post traumatic encephalopathy Herpetic viral encephalitis Anoxia Subarachnoid hemorrhage Pick's dz ( frontotemporal dementia and degradation of the brain) Alzheimer's dz Bilateral temporal infarction Focal status epilepticus BASICALLY BILATERAL TEMPORAL CORTEX AND AMYGDALA LESIONS
