Functionally what is the limbic system?
The parts of the CNS that control:
Why is the limbic system called the limbic system?
Because limbic means rim, and the original structures of the limbic system were the rim of cerebral cortex surrounding the Diencephalon structures
What are the major cortical components of the limbic system?
What are the subcortical components of the limbic system?
What are the major pathways between components of the limbic system?
What does the isthmus in the limbic system connect?
The cingulate gyrus to the parahippocampal gyrus
Anteriorly what does the cingulate gyrus curve under?
What is the underneath area called?
It curves under the genu of the corpus callosum and the area it connects to is the subcallosal cortex
What is the subcallosal cortex adjacent to?
The piriform cortex and olfactory tubercle
What does the piriform cortex merge with posteriorly?
The uncus and the rest of the parahippocampal gyrus
What is the major role of the hippocampus?
Formation of declarative memory through the papez circuit
What is the cortical structure of the hippocampus?
What kind of neurons are in the hippocampus?
It is a primitive structure so it has only 3 or 4 layers (like the closely related dentate gyrus)
The hippocampus is made of pyramidal cells arranged in a C formation intertwined with the dentate gyrus
What are the four pyramidal cell zones in the hippocampus?
Which type is especially susceptible to ischemia and is devastated in Alzheimer’s disease?
CA1-CA4 from closest to furthest from the subicular cortex
CA1
The hippocampus is an unfolding of what?
The medial temporal lobe
Where does the hippocampus receive input from?
Via what pathway?
The entorhinal cortex (part of the parahippocampal gyrus) via the perforant pathway
Where does most of the output from the hippocampus go?
What is the subicular cortex? What cells originate here?
An area right next to the hippocampus that gives rise to the axons of the fornix.
What two areas give rise to axons of the fornix?
2. Ca1 cells in the hippocampus
What efferent of the hippocampus travels via the postcommisural fornix?
Diencephalon (mammillary bodies, anterior thalamic nucleus)
What efferents from the hippocampus travel via the precommisural fornix?
Septal areas
What is the role of the prefrontal cortex?
Behavioral planning
Social interaction
Working memory
Affect and mood
What are the three major areas of the prefrontal cortex?
What is damage to the prefrontal cortex associated with?
Personality change
What does the prefrontal cortex receive input from?
Where does the Amygdala lie?
Anterior temporal lobe in front of and superior to the hippocampus