Association fibers are
axons that connect
cortical areas within the same
cerebral hemisphere.
In human neuroanatomy,
axons (nerve fibers) within the brain, can be categorized on the basis of their course and connections as association fibers,
projection fibers
The projection fibers consist of efferent and afferent fibers uniting the cortex with the lower parts of the brain and with the spinal cord. In human neuroanatomy, bundles of axons (nerve fibers) called tracts, within the brain, can be cate ...
, and
commissural fibers
The commissural fibers or transverse fibers are axons that connect the two hemispheres of the brain. In contrast to commissural fibers, association fibers connect regions within the same hemisphere of the brain, and projection fibers connect ...
.
The association fibers unite different parts of the same
cerebral hemisphere, and are of two kinds: (1) short association fibers that connect adjacent gyri; (2) long association fibers that make connections between more distant parts.
Short association fibers
Many of the short association fibers (also called arcuate or "U"-fibers) lie immediately beneath the gray substance of the cortex of the hemispheres, and connect together adjacent
gyri.
Some pass from one wall of the sulcus to the other.
Long association fibers
The long association fibers connect the more widely separated gyri and are grouped into bundles.
They include the following:
Diffusion tensor imaging
Diffusion-weighted magnetic resonance imaging (DWI or DW-MRI) is the use of specific MRI sequences as well as software that generates images from the resulting data that uses the diffusion of water molecules to generate contrast in MR images. It ...
is a non-invasive method to study the course of association fibers.
See also
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Interneuron
Interneurons (also called internuncial neurons, relay neurons, association neurons, connector neurons, intermediate neurons or local circuit neurons) are neurons that connect two brain regions, i.e. not direct motor neurons or sensory neurons. I ...
*
Tractography
References
External links
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Cerebral white matter