Reactive changes in neurons of the raphe serotonergic ом nucleus of after experimental stress in the neonate period and buspirone therapy

  • Andrey Vsevolodovich Droblenkov St. Petersburg State Pediatric Medical University
  • Alexandr Vladimirovich Pivnev St. Petersburg State Pediatric Medical University
  • Vasiliy Alexandrovich Pyzhov St. Petersburg State Pediatric Medical University
  • Irina Pavlovna Butkevich Pavlov Institute of Physiology, Russian Academy of Sciences
  • Viktor Anatol’evich Mikhailenko Pavlov Institute of Physiology, Russian Academy of Sciences
  • Tat’yana Nikolaevna Shimaraeva St. Petersburg State Pediatric Medical University

Abstract

The identification of the raphe nucleus neurons reactive changes after experimental stress in the newborn period is necessary for a better understanding of the mechanisms of damage and adaptation of the serotonergic system in the brain during postnatal development. It is well known that the raphe serotonergic nucleus is the largest source of serotonergic nerve fibers through which the connection with the hypothalamus and other projection centers of “positive reinforcement system”. The study of reactive changes raphe nucleus neurons after experimental stress in the newborn period is necessary for a better understanding of the mechanisms of damage and adaptation of the serotonergic system in the brain during postnatal development as well as for possible correction of behavioral disorders. In 37 day old rats after injection of buspirone (experimental animals) and control (injected with physiologists cal solution) studied pain response in the formalin test (2.5 % injection solution of formalin in 1.0 l of a sole of the hind limb). In sections macrocellular raphe nuclei stained by Nissl, counted the number of unmodified, hypochromic, shrunken and hyperchromatic, shadowly cells, established area little changed neurons. Measured as the distance between the bodies of neurons and glial cells between the bodies and the bodies of neurons. It was found that after the simulation of stress in a large raphe nucleus neurons developing degenerative and compensatory-adaptive changes. Reduces the number and size of bodies of neurons containing substance Nissl, wrinkling occurs, strengthening and weakening of staining, the growth of the share of shadowly neurons. Also activated glioneuronal and interneuronal relationships. Reactive changes in the cells exposed to the compensation correction drugs that block receptors for serotonin.