Mo on the "Connectome": "Not so fast"

Mo from Neurophilosophy linked to an article, Not so fast, written for seedmagazine.com re: his perspective on the ambitious project of mapping all the pathways and connections there are in the brain.

He says confounding factors include neuroplasticity, ignoring the functions of neuroglia, and ordinary small-scale variations that occur:

"the connectome apparently ignores the phenomenon of neuroplasticity.

Plasticity refers to the brain’s ability to physically alter its structure in response to experience. Far from being immalleable, as was once thought, the brain is a highly dynamic organ. Neurons can sprout new connections within minutes of a given stimulus, and entire neural pathways can be rerouted so that function is recovered after a brain injury.

The connectome also disregards the functional importance of neuroglial cells, another class of cells which are found in the nervous system and which outnumber neurons by at least 10 to 1. Once thought to merely provide structural and nutritional support for neurons, glia have, in recent years, come into their own as key players in the brain. As well as performing the roles initially ascribed to them, glia carry out a whole host of other vital functions, including monitoring neuronal health, identifying damaged neurons, and regulating synaptic plasticity. They are also known to be capable of communicating not only with one another, but also with neurons. A map of brain connectivity cannot therefore be complete without taking glia into account.

Finally, although the large-scale connections are very similar among individuals, there are significant variations at smaller scales."

My bold.

More from Lausanne: Mapping the Structural Core of Human Cerebral Cortex

This paper (open access) has just been published online: Mapping the Structural Core of Human Cerebral Cortex. Researchers in Switzerland are finding ways to combine imaging techniques to deepen understanding of how the brain functions at rest and at work.

AUTHOR SUMMARY
"In the human brain, neural activation patterns are shaped by the underlying structural connections that form a dense network of fiber pathways linking all regions of the cerebral cortex. Using diffusion imaging techniques, which allow the noninvasive mapping of fiber pathways, we constructed connection maps covering the entire cortical surface. Computational analyses of the resulting complex brain network reveal regions of cortex that are highly connected and highly central, forming a structural core of the human brain. Key components of the core are portions of posterior medial cortex that are known to be highly activated at rest, when the brain is not engaged in a cognitively demanding task. Because we were interested in how brain structure relates to brain function, we also recorded brain activation patterns from the same participant group. We found that structural connection patterns and functional interactions between regions of cortex were significantly correlated. Based on our findings, we suggest that the structural core of the brain may have a central role in integrating information across functionally segregated brain regions."

The various images represent information gained from various kinds of investigative technique produces - this image (from the paper) is a computer integration/ combination..

July2: Back inside this post for a moment to drop a link from Mo's post at Neurophilosopy about this topic. Please go and read it - it contains much more analysis on the paper and the implications of the research, and links to this amazing picture of white matter tracts in the brain. The three main classifications of white fibers (association, commissural and projection) are clearly visualized: