Neuropeptides (protein molecules) are synthesised in the neurons, helps to communicate the impulse from the stimulant to the receptor. Neuropeptides are responsible for regulating a various physiological functions including development, metabolism, water and ion homeostasis, and as neuromodulators in circuits of the central nervous system. Neuropeptides are different from neurotransmitters because, former releases in the haemolymph and the later releases in the neuro-neuro junction or in the neuro-muscular junction. The first neuropeptide isolated from Periplanata Americana was protocolin in the year 1975 which helps in muscle contractions in hindgut, reproductive, skeletal and heart muscle. At present a total of 4782 insect neuropeptide records were obtained which perform various related physiological functions. Thus it paves the way for the generation of novel type of putative insect control agents based on backbone cyclic (BBC) peptidomimetic antagonists of insect-neuropeptides. At present four different neuropeptides such as proctolin, kinin, pheromone biosynthesis activating neuropeptide (PBAN) and allatostatin were studied thoroughly and their biologically active sequence were identified.
