We are aware of thinking and acting, and we typically think this is what neurons and brains are for. Their deeper functions in regulating the body, either directly or through neuro-hormonal and neuro-immune interactions are largely unconscious and therefore neglected. This talk introduces theoretical models and experimental data suggesting an even deeper and evolutionarily older function of nervous systems: regulating the size and shape of the body. If these models are correct, the original function of neurons was the regulation of cell proliferation and differentiation. Neurons still perform these functions, from early embryogenesis through adulthood. We may even, sometimes, be aware of them. Recognizing this gives a new meaning to "embodied cognition."
