Hints from statistical physics and graph theory to build synthetic connectomes: Comment on ``What would a synthetic connectome look like?'' by I. Rabinowitch

The development of the first living being with a synthetic genome, the bacteria Mycoplasma mycoides JCVI-syn1.0 [1], generated a whole range of unfolding in science: from ethical and social implications, to biotechnological applications, to scientific understanding [2]. This was the inception of Synthetic Biology. Rabinowitch [3] proposed to do the same within Neuroscience: forward-engineering synthetic connectomes and building them inside living beings. The author lists three ways capable of changing brain connections in vivo: experience, brain activity, and genetics. The first one relies on sensorimotor experiences leading to the wiring/rewiring of brain connections (by neurofeedback, for example, in therapeutic applications). Activity-based manipulations may artificially shape connectivity through the insertion of spatiotemporal activation patterns that correlate with specific neurons firings, reinforcing synapses through spike-timing dependent plasticity (STDP). Finally, genetics is often used to manipulate the expression of protein and ionic channels throughout the membrane of the neurons, affecting its overall performance in propagating signals and making synapses. As opposed to correlation studies, the author argues that this approach could lead to understanding causal links between the structure and function of the brain.