Neuroplasticity is the ability to undergo biological changes ranging from the cellular level to large scale changes involving cortical remapping. Such changes often happen as a result of psychological experiences. During such changes, the brain engages in synaptic pruning, deleting the neuronal connections that are no longer necessary or useful, and strengthening the useful ones.
Though Yoga literally means "yoke", "unify", it is also a developed system of philosophy, as well as a practical method to realise the ultimate truth originated in ancient India and codified mainly by Patanjali. Let us look at what makes Yoga different from other systems of thought, so we can understand its metaphysical, ontological, psychological and practical view of life. Historically this may have developed well before Christ and developed side by side other systems of thought in ancient India, but we can clearly see the correlation of Yoga with the Sankhya system. In spite of the connection with the Sankhya doctrines, Yoga differs from it on matters of psychology, ethics etc. and brought a scientific approach to disciplinary practices with rigour and great clarity.
One of the greatest contributions of India is the metaphysics of self knowledge called Samkhya, which says the knowledge of an object, the object itself and the process of knowing is all one. This is the essence of wisdom and experientially accessible for anyone through the practice of Yoga. Yoga thus is the methodology to test this hypothesis of samkhya, just like we do the lab experiment to prove a theorem in modern physical sciences.
There is no single English word to convey the meaning of the Sanskrit word prana, the nearest word in English is probably "life energy" or "vital energy" that permeates the whole universe and our bodies. The breath that goes in and out of our bodies connect the microcosm within to the macrocosm and if one breath that goes out does not come back life is finished, isn’t it? Prana is in a way our real Mother in whom we are born, sustained and to whom we go back to. The inhalation is the inspiration for life itself and exhalation is the main expiration of toxins from our biological system that keeps us alive and conscious. Breath, like a power plug acts as the source of our entire energy supply to every cell.