|Location of the thalamus (in red)|
Why the thalamus? Located between the cortex and the midbrain, this cerebral structure is the main relay station of the brain: it is connected by fibers to virtually the entire cerebral cortex. In addition, the thalamus is related to the regulation of consciousness and sleep, and it is also closely related to language. The relationship with language has been proven in case studies involving thalamic lesions and electrical stimulation of the thalamus. However, it is still unclear whether this relationship is due to the connection between the thalamus with cortical regions related to language, or due to its involvement in the integration of language functions via memory.
Moreover, the thalamus has been linked to some of the most common language disorders, including dyslexia, a condition in which individuals with normal intelligence have serious problems learning to read. Dyslexia is the most common neurobehavioural disorder in children, on which it has a terrible impact: it causes severe disadvantages in school development, education and self-esteem that greatly increases the risk of social marginalization later in their lives.
This project aims for building a detailed atlas of the thalamic nuclei using multimodal imaging data from autopsy brain samples, and for creating companion image analysis tools that can use the atlas to analyze the thalamic nuclei in in vivo brain MRI data (that is, from living people) from neuroimaging studies. The project consists of four major steps. First, we plan to acquire ultra-high resolution MRI data of the autopsy samples. Since these samples don’t move (for obvious reasons), we can make the MRI acquisition very long therefore with very high resolution. Second, we will slice the brains to perform a microscopic anatomical study (known as “histology”) of the samples. The ultra-high resolution MRI and the histology images will allow us to build a thalamic atlas with very high level of detail. Third, we will create the tools that enable us to use the atlas in the analysis of in vivo data. And fourth, we will make the tools publicly available and apply them to a dyslexia study at the BCBL. Hopefully, the new tools will allow us to better understand this disorder, while enabling researchers at other institutions to improve their understanding of this cerebral structure by carrying out analyses at a higher level of detail - compared with current tools.
I will regularly post here with the progress of the project; stay tuned!