Our study aims to analyse and map the cytoar­chi­tec­ture of the human hypothal­a­mus in histo­log­i­cal sections of 10 postmortem brains. As a result, we want to develop a high-resolu­tion 3D recon­structed histo­log­i­cal model of the hypothal­a­mus and its nuclei as a tool for assess­ing the struc­ture-function relation­ship and a proba­bilis­tic cytoar­chi­tec­tonic map of the hypothal­a­mus that will reflect the variabil­ity of hypothal­a­mic nuclei between individ­ual brains, in terms of size and location in standard refer­ence space.

The hypothal­a­mus is part of the diencephalon that plays a key role in maintain­ing homeosta­sis of neuroen­docrine, behav­ioural and autonomic processes. It consists of several nuclei, which differ in their microstruc­ture, connec­tiv­ity and function.

Study­ing struc­ture-functional relation­ships of the hypothal­a­mus is becom­ing more feasi­ble with increas­ing spatial resolu­tion of modern neuroimag­ing in the living human brain. However, it is diffi­cult to local­ize brain activa­tions in the function­ally differ­ent nuclei, which are hardly visible in routine MR. Currently, there are no maps, which inform neuroimag­ing studies about the microstruc­tural segre­ga­tion of the hypothal­a­mus in 3D space.

We there­fore aim to develop a cytoar­chi­tec­tonic map of the hypothal­a­mus in the BigBrain – a high-resolu­tion 3D-recon­structed histo­log­i­cal model of the human brain, using a deep-learn­ing based mapping tool. The result­ing map will capture the shape and extent of the hypothal­a­mic nuclei with cellu­lar preci­sion. Thus, the map will bridge the micro­scopic struc­ture of the hypothal­a­mus and MR-based studies at the macroscale.

Also, we will develop proba­bilis­tic cytoar­chi­tec­tonic maps of the hypothal­a­mus. There­fore, we will study serial histo­log­i­cal sections of 10 postmortem brains and map the nuclei over their full extent. Maps will be trans­ferred to standard refer­ences space to link them with neuroimag­ing data, to serve as an anatom­i­cal refer­ence for studies of healthy brains and patients. They will be freely avail­able to the scien­tific public.