Neurosciences - A neurosurgeon's perspective

The advancements in the field of science in the past fifty years have highlighted the need to integrate all fields of human endeavours and have emphasised interdependency of various disciplines. The separation of humanities, therefore, from neurosciences is a preposterous practical joke on all thinking men. With the human genome project on the anvil, biotechnology is making significant headway holding out promise for organ regeneration. Macro evolution is over, but micro-evolution continues in the brain. Neural Darwinism thus, continues to evolve as long as individual remains conscious and has memory. In the milieu of widely varying internal physiological mechanisms and external stimuli, an alternative theory to preprogrammed directionalism is proposed by three mechanisms namely developmental variation and selection, experiential selections and reentrant signalling. Reentrant signalling reorients and correlates the external inputs leading to psychic development preceding the development of consciousness. The cholinergic and aminergic neuro-modelling systems are well suited to serve as value systems. The main achievement of consciousness is to bring together the many categorizations involved in perceptions into a SCENE. Another part of evolution involved capacity of reentrant signalling to be guided by a value system where it is provided with a lot of choices. With 10(13) neurons and 10(16) connections, freedom of choice may manifest into a 'Buddha' or a 'Hitler'. As part of the evolutionary process, it was interesting how capacity to categorize the need to worship by referring to environment outside evolved into a search within our minds. As the next stage of evolution, neuroscience may, thus, serve as the next gateway to understanding the mind and soul.