Limbic System Anatomy
Overview
Limbic gyrus
- Cingulate gyrus
- Parahippocampal gyrus
Intralimbic gyrus
Important anatomic landmarks: the corpus callosum, basal frontal lobe, thalamus, and the septum pellucidum.
Select Papez Circuit Components
- Anterior nuclei of the thalamus
- Mammillary body of the hypothalamus
Select Key Components
Limbic gyrus (which forms the outer limbic ring)
- Cingulate gyrus (lies above the corpus callosum)
- The anterior cingulate gyrus is part of the anterior network of motivation, attention, and behavior and is associated with the amygdala.
- The posterior cingulate gyrus is part of the posterior network of learning and memory and is associated with the hippocampus.
- Parahippocampal gyrus
- Channels information to and from the hippocampus to help in memory consolidation; an efficient parahippocampal gyrus is necessary for effective memory processing.
- Uncus (the gyral fold at the anterior tip of the parahippocampal gyrus).
Intralimbic gyrus (which forms the intralimbic ring).
Amygdala (aka amygdaloid body, almond-shaped*)
The simplest way to understand the amygdala is to divide it into a corticomedial group and a basolateral group. Both groups connect to a wide variety of brain regions:
- The corticomedial group connects, most notably, to the olfactory system and hypothalamus for autonomic function.
- The basolateral group connects, most notably, to the thalamus and prefrontal cortex for more conscious-related processes such as sensory processing of visual, auditory, and somatosensory stimuli.