Insulin controls the levels of blood sugar by inhibiting glucose release from liver and by stimulating glucose utilization in muscle and adipose tissues. In addition to its peripheral effects, insulin influences circulating glucose levels by modulating glucose production and its metabolism through central nervous system. But it is presently not well known whether the central effect of insulin on plasma glucose is mediated by directly or indirectly through CNS actions. The autonomic nervous system exerts a dual control over insulin secretion. The parasympathetic nervous system can augment insulin secretion and the sympathetic nervous system can produce a net impairment of insulin release.