Identification of a key gene to make the distribution base of senses in the brain
The research team of Brain/Liver Interface Medicine Research Center, Kanazawa University, Japan has identified a gene that is essential to the formation of the thalamus. The thalamus is an important brain region working as a hub for various sensory information distribution in the brain. Since abnormality of thalamus leads to sensory impairment, it is expected that the current research leads to elucidation of sensory abnormality caused by various diseases.
We humans recognize the outside world by using the senses, i.e., vision, touch, and so on. Therefore, correct sensation is absolutely necessary for our healthy daily lives. Also, abnormality of sensation may be a big impediment against the living, so understanding of the mechanism of the brain regions responsible for sensation is of primary importance.
Senses arising at various parts of our body, like the eye and the skin, are sent to the cerebral cortex in the brain for information processing, but before that, in fact, the senses are gathered at the part of brain called the thalamus located in the very center of the brain. The thalamus can be regarded as the distribution hub of sensory information; almost all sensory informations pass through the thalamus. Thus, any abnormality of the thalamus caused by various diseases may lead to severe abnormality of sensation. The thalamus is, therefore, the extremely important part of the brain, although so far, little is known about the mechanism of formation of the thalamus during fetal development.
The research team searched for genes essential to the formation of the thalamus during fetal development, and found that the loss of activity of Foxp2 gene resulted in the lack of the big portion of the thalamus, which processes the tactile sensory information, in the thalamus. More specifically, analyses of mice that have abnormality in Foxp2 gene revealed malformation of the thalamus including the significant regression of the part called VP nucleus, which processes tactile sensation. These findings demonstrate that Foxp2 is a key gene, extremely important in the correct formation of the thalamus during fetal development. Based on the current findings, it is expected that the mechanism of sensory abnormality caused by various diseases will be elucidated.
This study was published online in a British scientific journal, ‘Cerebral Cortex’, on July 6, 2016.
Figure. Mice with impaired Foxp2 gene functions were found to have considerably smaller thalamus; especially, the part of thalamus for tactile sensing was largely missing.
Title: Foxp2 regulates identities and projection patterns of thalamic nuclei during development
Journal: Cerebral Cortex (2016)
Authors: Haruka EBISU1,2, Lena IWAI-AKEKOSHI2, Eriko FUJITA-JIMBO3, Takashi MOMOI4, Hiroshi KAWASAKI1,2
1Kanazawa University, 2University of Tokyo, 3Jichi Medical University, 4Tokyo Medical University
The Global Centers of Excellence program and the Grant-in-Aid for Scientific Research from the Ministry of Education, Culture, Sports, Science and Technology-Japan,Takeda Science Foundation;Life Science Foundation of Japan,Teijin-Kumura scholarship (to H. E.) ;Research Fellowship for Young Scientists from Japan Society for the Promotion of Science