The role of neurotrophic factors and navigation molecules in the processes of brain development and the formation of predisposition to mental illness

Neurotrophic factors and guidance molecules are key regulators of the processes of brain formation, growth and maturation. During early stages of embryogenesis, they stimulate proliferation and differentiation of neural progenitors, direct their migration, and promote the establishment and maintenance of interneuronal connections. Timely expression and correct functioning of multiple molecules, primarily neurotrophic factors, guidance molecules and their receptorsprovide the high coordination of these processes. And this makes it possible to form the brain as an integral structure and lay the basis for its cognitive and mental activity during a short period of prenatal development. On the contrary, aberrant activity or stoichiometry of such molecules, spatial or temporal impairment of their expression, can disrupt the formation of distinct brain structures or their adequate interaction and lay a redisposition to a number of psychiatric and neurological disorders such as schizophrenia, bipolar disorder, autism, obsessive-compulsive disorder, attention deficit hyperactivity disorder, epilepsy and others. This is confirmed by a number of clinical observations, animal studies and in vitro models. Despite the obvious contribution of brain ontogenesis onto the development of psycho-cognitive features of personality and the formation of predisposition to mental diseases, very little attention is paid to study ofbrain ontogenesis and molecules involved within this context. Apparently, it is difficult to identify the morphogenetic molecules and signaling cascades involved in due to the complexity of brain ontogenesis and the polygenic nature of mental disorders. All this restricts our understanding of the etiology and pathogenesis of mental disorders and does not allow their timely diagnosis and prevention. The aim of this review is to summarize the known facts about the possible role of neurotrophic and guidance molecules in the processes of brain development and pathogenesis of a number of mental disorders, and to emphasize the need for more research in this area of molecular psychiatry.