Limbic System Flashcards
Limbic function
1) Emotion
2) memory
Olfactory Bulb Diagram
1) Strong communication to memory and emotion
- some of the strongest memories w/smell
2) Olfactory sensory neuron extends through the cribiform plate and olfactory epithelium
- receives signal
- synapse on cells in Glomeruli/olfactory bulb
- tufted cell and Mitral Cell
3) Tufted Cell and Mitral Cells
- both travel to the lateral olfactory tract
4) Mitral Cells project to 5 different regions of olfactory cx:
- anterior olfactory nucleus-> contralateral olfactory bulb via medial olfactory stria and anterior commissure
- olfactory tubercle
- piriform cortex
- parts of amygdala and entorhina cx
5) Tufted cells project primarily to:
- anterior olfactory nucleus
- olfactory tubercle
Olfactory bulb splits into:
1) Medial Olfactory Stria or Anterior Commisure
- contralateral olfactory bulb
2) Lateral Olfactory Tract
Vomeronasal Organ
1) receptors in nasal cavity
2) sends info to accessory olfactory bulb
- Mitral Cell-> AMYGDALA only
3) Pheromone Pathway
- only animals, not humans
- Pheromones drive the sexual behavior when females are ovulating
- Unconscious Process
Enterohinal Cortex
1) Major input into hippocampus
Hippocampus
Memory formation
-memory is laid down here first
Septal Area
Pleasure center
-strong connection to Nucleus Accumbens
NT involved in Pleasure Complex/Addiction
1) Dopamine
2) Endorphins-opoid
3) Enkephlin-opoid
4) Serotonin
5) GABA
Opiate Agonist
1) Endorphin
2) Enkephaline
Opiate Antagonist
1) Naltrexone
- used for alcoholic to take the pleasure out of drinking
Basal Nucleus of Meynert (BNM)
1) AKA substantia innominata
2) emotion, motivation, and memory
3) sends Ach efferents throughout the cortex
4) Degenerates with Alzheimers->basis for memory loss
Nucleus Accumbens
1) Addiction
2) dopamine receptors
3) Drugs like cocaine enhance dopamine activity in nucleus
Septal Nuclei
1) Pleasure Center/Addiction
2) strong dopaminergic input
3) When stimulated-euphoric feeling/orgasm
Ventral Tegmentum Area (VTA)
1) Found in midbrain
2) Pleasure center/addiction
3) Dopamine as NT
4)Dopamine projects to:
-Nucleus Accumbens
-Limbic system
-prefrontal cortex
-insular cortex
&project back to VTA
5) major center for addiction
Nicotine
1) most addictive chemical substance
2) works w/ Nucleus Accumbens
Fornix
1) some of the fibers connect to:
- hippocampus
- mammilary bodies
2) some fibers go into:
- hippocampal commisuri
- connecting to other side
3) Afferent and Efferent fibers found here
Fimbria of hippocampus
1) Major efferent pathway
- goes through fornix
- major targer=mammilary bodies
Amygdala location
slightly anterior to hippocampus
Mammillary Bodies Fxn:
Memory Formation
Major vs Minor Afferents: Hippocampus
CHASE U
1) Cingulate gyrus
- higher cortical areas->cingulate gyrus->entorhinal cortex-> hippocampus
2) Entorhinal Cortex
- major input into hippocampus
3) Amygdala
4) Hypothalamus via fornix
5) Septal Area via fornix
6) Uniculate Fasciculus
- tract from frontal cortex to temporal lobe
- minor input to hippocampus
Major vs minor Efferents: Hippocampus
FANTHEMS
1) Frontal Cortex
2) Nucleus Accumbens
3) Septal Nucleus
4) Mammilary Bodies
5) Thalamus-Anterior Nucleus
6) Amygdala
7) Hypothalamus
8) Entorhinal Cortex
Cingulate Gyrus
-function
1) Important role in maternal behavior
Left Anterior Cingulate Gyrus Lesion
1) Right side emotional facial paralysis
-interferes w/limbic connection w/facial nerve
(blank Face)
-CN7stays intact
CA
Pyramidal Cells of hippocampus