Corpus callosum
From Psy3242
What Is It?
The Corpus Callosum, which contains more than 200 million nerve fibers, connects the left and the right hemispheres of the brain. It is the largest pathway in the human brain and runs right down the middle. When it comes to communication between both hemispheres, the Corpus Callosum is the main pathway used. Communication is needed when the body needs to coordinate movement or create complex thoughts and ideas. There are other smaller pathways the brain also uses to communicate between hemispheres, but the Corpus Callosum is the most important. The next main pathway is the Anterior Commisure, but it contains a mere 50,000 nerve fibers as compared to the 200 million of the Corpus Callosum.
Development
As the human body develops, the Corpus Callosum does along with it. The actual structure of the Corpus Callosum finishes developing between 12 and 16 weeks in-utero; however, although the structure has finished growing, the fibers in it continue to become more effective and efficient as one grows into an adolescent. By the age of 12, the Corpus Callosum will function just as well as it will in adulthood.
Disorders of the Corpus Callosum
The Corpus Callosum does not complete growth in all people. In some developmental cases, the fibers will not completely connect the two hemispheres. This occurs in utero, and if the pathway is not created during prenatal development, it never will develop correctly. Some people are also born completely without a Corpus Callosum. These disorders can be a result of prenatal infections or viruses, genetic abnormalities, toxic metabolic conditions, like Fetal Alcohol Syndrome, and blockage of the growth of the Corpus Callosum by something like a cyst in the fetus. A few names of disorders are Agenisis of the Corpus Callosum, Hypoplasia, and Dysgenesis. Many people with an abnormal Corpus Callosum live completely healthy lives, while others may need medication through their lifetime. A person with a CC disorder may have Epilepsy, a slowdown in reaching the milestones of development (crawling, walking, talking, etc.), and frequent migraine headaches. With medication or other therapy, person suffering from a CC disorder can lead completely normal lives.
The corpus callosum can be devided surgically in order to keep severe seizures from spreading across hemispheres or, prevent the seizures from occuring. This procedure is known as a corpus callosotomy and results in split-brain (see also,neurosurgery).
Interesting Fact:
The Harvard neuroscientist Gottfried Schlaug has shown that the front portion of the corpus callosum, the mass of fibers connecting the two cerebral hemispheres, is significantly larger in musicians than non-musicians, and particularly for musicians who began their training early.
