Update on Limbic Connections in Human Brain: A Possible Closer Relationship Between Brain Processes and Visceral Information.
The limbic system includes cortical and subcortical brain structures involved in several functions, first of all emotional and memory processes and integration. Two key structures of the limbic network are hippocampus and
amygdala; their connections with the other brain regions are allowed through a number of white matter pathways, including cingulum, uncinate fasciculus and fornix.
All these pathways were studied by means of invasive approaches in animals as well as by means of MRI techniques, e.g. diffusion based tractography. These methods resulted very useful for the non-invasive study, in vivo, of these limbic brain connections, as well as to show new possible pathways, e.g. the cerebellar limbic one.
Recently, new insights regarding possible limbic functions came from a study conducted by means of advanced tractographic algorithms. The main goal of the latter paper was to investigate subtentorial limbic
connections in healthy humans; this was an interesting point, since these connections were previously investigated only in animals by means of viral tracing techniques.
These previous studies revealed extensive connections of both amygdala and hippocampus with brainstem nuclei,
as well as connections with the periphery of the body through spinal projections. By means
of constrained spherical deconvolution based tractography, Arrigo and colleagues
reported and described hippocampal and amygdalar connections with midbrain, pons and bulb
as well as connections with cervical spinal cord.
Radiol Open J. 2016; 2(1): e1-e3. doi: 10.17140/ROJ-2-e004