Nerves cannot be cultured in artificial medium due to their complex requirements for growth and differentiation, which are not fully replicable outside their natural environment. Cultured neural networks have been successfully developed, demonstrating capabilities such as learning and memory, as evidenced by research like Baruchi and Ben-Jacob's work on neuro-memory chips and experiments with rat neurons controlling robotic systems. Neurons do not undergo cell division; however, neural stem cells in the brain can differentiate into neurons or glial cells. Once differentiated, neurons typically do not divide, although there are indications that they might revert to a precursor state under certain conditions.