In humans, the corpus callosum is made of millions of nerve fibres (over 190 million). In early pregnancy, many systems are involved in guiding corpus callosum fibres to connect the hemispheres. The first corpus callosum axons cross from one side to the other around 13-14 weeks post conception and the entire length of the callosum is complete by week 20. Soon after birth the nerve fibres become covered with an insulating coat (made of myelin), which helps information travel faster along the axons. The myelin coat starts to form within the first year of life and makes the corpus callosum expand in size further until its shape resembles that of an adult. There is also some fine-tuning of the connections between nerve fibres, where new connections form and other connections are removed. Our brains, and therefore our corpus callosum, continue to grow during childhood and adolescence as they become more effective and efficient. The eventual size and shape of a normal corpus callosum can vary between individuals.

FAQs Archive - Page 3 of 3 - Welcome to Corpal

Q: How often does it happen?

Reported figures in the medical literature vary widely. The most recent large scale study from the US in 2008 estimated an annual incidence of 1.8 per 10,000 babies born. The incidence in boys and girls are approximately the same, although the underlying causes for either sex may not be. It is widely acknowledged that callosal abnormalities are more common in individuals with learning and developmental disabilities.

Q: Are there other connections?

The human brain has several, much smaller, bundles of nerve fibres that connect the right and left hemispheres, such as, the anterior, posterior and hippocampal commissures.

Q: What is the Corpus Callosum?

The corpus callosum is the largest bundle of connections between the right and the left sides (hemispheres) of the brain. It is often described as a “bridge” that enables communication between the two halves of the brain.

FAQs

How often does it happen?

Are there other connections?

How does it develop?

What causes abnormal development of the corpus callosum?

What is the Corpus Callosum?