Table of Contents
What is fornix in the brain?
The fornix is a white matter bundle located in the mesial aspect of the cerebral hemispheres, which connects various nodes of a limbic circuitry and is believed to play a key role in cognition and episodic memory recall.
How is fornix related to behavior?
The tumors that involve the fornix can cause loss of memory and behavior of a person. Profound changes can be seen in the behavior of patients with the fornix involvement. The involvement of fornix also causes memory dysfunction. It results in anterograde amnesia and retrograde amnesia.
What type of white matter is fornix?
The fornix is a C-shaped bundle of white matter that is found in the mesial aspect of the cerebral hemispheres, below the corpus callosum. The fornix is an important part of the limbic system, and represents the largest single pathway of the hippocampus, connecting it to various subcortical structures.
Is the fornix white or GREY matter?
Roughly C-shaped, the fornix extends from the hippocampus to the mammillary bodies of the hypothalamus and the anterior nuclei of the thalamus. It is a curvilinear bundle of white matter fibers that begins as a group of myelinated fibers called the alveus. The alveus joins to form the fimbria of the hippocampus.
Where does the fornix end?
The anterior fibers (precommissural fornix) end at the septal nuclei of the basal forebrain and nucleus accumbens of each half of the brain.
Where does the fornix receive its input?
The hippocampus receives inputs via the precommissural branch of the fornix from the nucleus basalis of Meynert, which is a portion of the substantia innominata and which in turn is a portion of the septal nuclei.
What is the function of the corpus callosum?
The two hemispheres in your brain are connected by a thick bundle of nerve fibres called the corpus callosum that ensures both sides of the brain can communicate and send signals to each other.
Is the fornix part of the brain?
The fornix (meaning “arch” in Latin) is a C-shaped bundle of nerve fibers in the brain that acts as the major output tract of the hippocampus. The fornix also carries some afferent fibers to the hippocampus from structures in the diencephalon and basal forebrain. The fornix is part of the limbic system.
How does damage to the hippocampus affect the fornix?
Damage to the hippocampus and other mesial temporal lobe structures, including the fornix, results in global inability to form new declarative memories.
Why is the fornix important to global cognitive function?
Involvement by inflammatory conditions such as multiple sclerosis may illustrate its importance in global cognitive function. An appreciation of forniceal atrophy may aid in assessment of mesial temporal sclerosis.
Which is a pathologic condition of the fornix?
Pathologic conditions involving the fornix include congenital absence, tumors, infection, multiple sclerosis, mesial temporal sclerosis (MTS), Wernicke encephalopathy, trauma, infarction, Alzheimer disease, and schizophrenia. The fornix is initially formed from the output fibers of the hippocampus ( Fig 1 ).
Where does the fornix end in the hypothalamus?
As has been described, the hippocampal output is largely via the fornix, ending in the mammillary bodies of the hypothalamus. Fibers from the mammillary bodies pass backward into the anterior thalamic nuclei via the mammillothalamic tract and then on to the cingulate gyrus ( 16 ).