Neuropeptides in the regulation of brain activity in normal and neurodegeneration

An analysis of the literature containing information on the participation of neuropeptides in the development of brain diseases was carried out. Changes in the production, processing and secretion of neuropeptides, the activity of signaling mechanisms with their participation are responsible for the formation of different variants of neurological deficits (cognitive, behavioral, etc.). As a rule, neuropeptides or otherwise biologically active molecules in the body can function as neurotransmitters, neuromodulators, or neurohormones that perform cognitive and behavioral functions. These biologically active molecules are localized in cells in secretory vesicles, which are delivered from the body of nerve cells to nerve endings and act through Gp-conjugated receptors. The action of neuropeptides has been significantly studied relative to pathological conditions of the brain. So, the mechanism of development of Alzheimer's disease is associated with a diverse spectrum of neuropeptides such as ghrelin, neurotensin, pituitary activating adenylates cyclase polypeptide, neuropeptide Y, neuropeptide P, orexin. This disease is characterized by the accumulation of amyloid β (represented by two forms - Api-42, Api-40) in the brain tissue, which is due to an imbalance in the activity of secretases. The target of action is the precursor protein (APP). The form of the Aβ1-42 peptide has a destructive effect on the cell, this is due to a multidirectional effect: damage to mitochondria, an increase in the sensitivity of neurons to the effects of glutamate, impaired calcium metabolism, and a slowdown in metabolic transformations of glucose. Aβ peptide is characterized by the performance of a key function in synaptic transmission of a nerve impulse and enhanced synaptic transmission between two neurons for a long time. The pathological picture of Alzheimer's disease is characterized by significant expression of apolipoprotein E (APOE) in the brain tissue, which forms local cell clusters of amyloid β with Aβ, a decrease in the number of neurons expressing proopiomelanocortin (POMC), neuropeptide Y (NPY) and agouti-like peptide (AgRP) genes that change brain activity. As a result, expression of genes responsible for the synthesis of proteins of the immune system, early development of neuroinflammation and activation of apoptosis is also noted. Thus, neuropeptides are considered not only as biomarkers of pathological conditions, but also as targets for pharmacological preparations.

neuropeptides, neurodegeneration, biomarkers, Alzheimer's disease