<p>Changes in the qualitative composition and quantitative content of phosphoinositide cycle metabolites and their involvement in the process of excitation along nerve s have been studied; regeneration of injured somatic nerves under the action of insulin-like growth factor-1 has been established. It was shown that when the nerve is excited, there is a decrease in the level of phosphatidylinositol and phosphatidylinositol-4,5-diphosphate and an increase in the content of phosphatidylinositol-4-monophosphate and phosphatidylinositol-3,4,5-triphosphate, which indicates an intensification of phosphoinositide metabolism under conditions of depolarization of the nerve fiber membrane, as well as a redistribution of fatty acids in the phosphatidylinositol fractions, diacylglycerol and free fatty acids. Nerve incision is accompanied by the accumulation of all forms of phosphoinositides and a decrease in the level of diacylglycerol in both the proximal and distal segments of the nerve, apparently as a result of inactivation of phosphoinositide-specific phospholipase C. Upon intramuscular administration of insulin-like growth factor-1 at a dose of 100 ng/kg, there is an intensification of phosphoinositide metabolism, accumulation of diacylglycerol and a decrease in free fatty acids. Using Raman spectroscopy, recording of action potentials and growth of cones, restoration of the physico-chemical state of the lipid bilayer and functional activity in the proximal segment of somatic nerves was revealed when insulin-like growth factor-1 was used, which correlates with our data on changes in the composition of the lipid fraction of injured nerves in the presence of the drug. We believe that insulin-like growth factor-1 is one of the factors of axonal regeneration and restoration of functioning of injured nerves, exerting its effect as a result of activation of phosphoinositide-specific phospholipase C and phosphatidylinositol-3-kinase signaling pathways.</p>