A metabolic strategy

An evolutionary perspective raises the important question What are the implications and/or potential benefits of restricted transsulfuration A key feature of neuronal cells is their ability to live for an entire lifespan without dividing, which is crucial for long-term retention of information in the form of synaptic connections within neural networks. If a neuron divides, it would lose all of its synapses and all of its information content, so a metabolic strategy must exist that keeps neurons out of the cell division cycle. Oxidative stress normally restricts neuronal division (Kruman, 2004), and limiting transsulfuration provides a mechanism by which neurons can indefinitely sustain a moderate level of oxidative stress. Thus, it can be proposed that the unique pattern of sulfur metabolism adopted by the brain may be critical for sustaining retention of information and for neuronal survival over the lifespan. 

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