<p>Academician of the Russian Academy of Medical Sciences Igor Petrovich Ashmarin was the head of the Department of Human and Animal Physiology of the Biological Faculty of Moscow State University for 20 years (1986–2006). This review covers four research directions into the neurotropic activity of regulatory peptides, implemented at the department under his leadership. The two most significant directions are the elaboration and study of the properties of original ACTH(4-10) analogues and tuftsin fragment analogues. They resulted in the creation of fundamentally new drugs – the nootropic heptapeptide Semax and the anxiolytic heptapeptide Selank, the range of clinical application of which continues to expand. The third topic, related to the assessment of the physiological activity of arginine vasopressin fragment analogues, is also currently developing. Interest in it is constantly growing due to the search for peptide molecules exhibiting antidepressant properties in very low doses. The main objective of the fourth direction was to evaluate acute and delayed (after chronic administration in the early postnatal period) neurotropic effects of enkephalin-like fragments of beta-casein—beta-casomorphins. We demonstrated their important role in regulating parent-offspring interactions in mammals. The obtained data are relevant for the areas of developing modern types of nutrition for newborns, as well as assessing the specifics of the influence of milk components on the “gut-brain” axis. Many ideas put forward by Academician of the Russian Academy of Medical Sciences I.P. Ashmarin and related to the areas of synthesis, phylogenesis and mechanisms of activity of regulatory peptides remain significant today, when research into the fundamental and clinically oriented properties of this group of compounds continues to develop intensively.</p>