Developing Neural Networks and Plasticity

There is mounting evidence that the role of astrocytes in central nervous system development, networking, and plasticity is more than significant. Once regarded as mostly supportive and protective of neuronal function—the neuron traditionally considered the more evolved brain cell—recent neuroscientific advances from functional magnetic resonance imaging (fMRI) and other interface technologies force us to reconsider the hierarchy of brain control. Pereira and Furlan propose an astrocentric theory for the role of astrocytes in cognition and behavior. In this theory, the neuronal pool functions to provide an unconscious “awareness” of our state via tripartite synapses to “Local hubs” subserved by protoplasmic astrocytes, while the widespread astrocytic syncytium (composed of all 5 astrocyte types) or “Master hub” correlates pooled data from neurons, the blood-brain barrier, cerebrospinal fluid, and other internal milieu (“panglial syncytium”) to make a final “judgment” that at some point crosses the threshold to human consciousness and behavior. The authors relate the Master hub function of astrocytes with the default mode network first described in fMRI, an imaging modality wholly dependent on measuring the blood oxygen level (or BOLD signal) in cortical capillaries. Notably, the part of the human default mode network that is active only in conscious states is identified as a slow cortical potential by He and Raichle.
Source: Seminars in Pediatric Neurology - Category: Neurology Authors: Source Type: research