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We are all connected: Major insights are emerging from human connectomes

Posted by on January 14, 2013 in Journal Club, Neuroscience, UCSD | Leave a comment

David Van Essen is from Washington University where he is an Edison Professor of Neurobiology and Department Head of Anatomy and Neurobiology.  He is also a principle investigator of the Human Connectome Project (HCP), a project designed to map the human connectome as accurately as possible in a large number of normal adults and make the data freely available to the scientific community using a powerful, user-friendly informatics platform.  Jointly with Dr. Kamil Ugurbil from UMinn, he is responsible for the overall management of the HCP’s consortium’s efforts as a whole.  Dr. Van Essen has been involved in mapping the structure and function of the primate cerebral cortex for over two decades and in 1991, Dr. Van Essen, along with Felleman, published a landmark paper which contained the following circuit diagram of the visual system.

This hierarchy shows 32 visual cortical areas, where color corresponds somewhat to location. 2 subcortical visual stages (the retinal ganglion cell layer and the LGN). plus several nonvisual areas (area 7b of somatosensory cortex, perirhinal area 36, the ER, and the hippocampal complex). These areas are connected by 187 linkages, most of which have been demonstrated to be reciprocal pathways.

This diagram has been used numerous time in talks about vision science and neuroscience in order to demonstrate the complexity of the visual system.  Nevertheless, this paper paved the way for Van Essen’s subsequent work to understand the relationship between function and structure.  His research over the past decade has focused increasingly on:

  • development of brain-mapping software;
  • development of neuroinformatics tools and promulgation of their use through outreach efforts;
  • studies of human brain structure in health, disease, and development;
  • development and promulgation of surface-based atlases that facilitate comparisons across individuals and across data types;
  • tractography, functional connectivity, and cross-modal comparisons.

Van Essen is optimistic about the future insights the HCP will provide and has many lofty goals for the next several years.  They will soon begin genotyping, likely including whole genome sequencing on twin pairs and non-twin siblings in order to attempt to understand the genetic component of brain connectivity and behavioral phenotypes.  Over the next decade, they expect that data-mining of HCP data will provide major insights in the following areas:

  • a far more accurate charting of brain parcellations (particularly neocortical and cerebellar parcels), brain networks, and their dynamics
  • a quantitative characterization of network variability across individuals
  • correlations between behavioral phenotypes and brain networks that provide a deeper understanding of the neural basis of individual variability

To find out about the latest exciting discoveries stemming from the HCP or from Van Essen’s Lab, please join us on Tuesday, January 15th at 4 pm in the CNCB auditorium for the weekly Neurosciences Seminar Series talk given by Dr. Van Essen entitled “The Human Connectome Project”.

Marvin Thielk is a first year in the UCSD Neurosciences Graduate Program. Marvin is currently beginning his rotation with E.J. Chichilnisky at the Salk Institute trying to apply his computational background to neuroscience.