Vip, or vasoactive intestinal peptide, is a 28 -amino-acid peptide with diverse functions. It belongs to a peptide family including glucagon, secretin, etc. [1]. VIP acts as a neurotransmitter, neuromodulator, and secretagog, influencing brain activity, neuroendocrine functions, cardiac activity, respiration, digestion, and sexual potency. It exerts its function via receptor-mediated systems, activating signal transduction pathways like cAMP [1].

VIP plays a regulatory role in the growth of early post-implantation rodent embryos, possibly regulated by extra-embryonic tissues [2]. In the hippocampus, it modulates synaptic plasticity, influencing learning and memory processes [3]. VIP also affects the proliferation of CNS and cancer cells [4]. In allergic diseases, it mediates immunological functions through interaction with specific receptors on immune cells [5]. In asthma treatment, VIP-MapA-α-alumina shows potential in alleviating pathophysiological symptoms [6]. In the cortex, VIP + interneurons in different layers have transcriptional differences [7]. In the motor cortex, VIP interneurons possess synapse-type-specific learning rules [8]. In the hypothalamic suprachiasmatic nucleus, VIP-neurons regulate blood glucose level through enhancing sympathetic activity [9].

In conclusion, Vip is a multifunctional peptide involved in numerous biological processes. Its role in embryonic growth, neural plasticity, cell proliferation, immune-mediated diseases, and glucose regulation has been revealed through in-vivo studies. Understanding Vip's functions can potentially lead to new therapeutic strategies for related diseases such as epilepsy, cancer, and allergic disorders.