2. NERVOUS SYSTEM

 

The nervous system is one of the first to respond to radiation effects, both local and general, affecting the entire organism (U.I. Moskalev, l99l).

 

Penetration of long-living radioactive elements (¹³⁷Cs,  ⁹⁰Sr) into the organism causes a pronounced loss of equilibrium of neuroactive amino acids and biogenic monoamines in various compartments of the central nervous system, specifically the exciting transmitter, such as aspartate and glutamate, and decelerating agents, such as gamma amino oleic acid (GAOA), glycin. The degree of expression of the process is determined by the duration of incorporation of radioisotopes by the organism.

 

A more intricate pattern of variations of the bank of biogenic amines and neuroactive amino acids under the effect of incorporated radioisotopes is noteworthy, compared with external irradiation, still a number of reconstructed effects (inhibition of the serotonin system, early activation of the GAOA-system) is comparable with the effect of moderate lethal and superlethal doses for experimental animals (V.V. Lelevich, E.M. Doroshenko, 1995).

 

Injury of the brain tissues can be due to the toxic effect of the highly reactive nitrogen oxide they contain (V.L. Sharygin, et al., 1994).

 

Incorporation of ¹³⁷Cs causes dysfunction of the vegetative nervous system, with the incidence of the elevated tone of the sympathetic nervous system being directly proportional to the quantities of the incorporated radioisotope. When its concentrations in the organisms of children exceed 100 Bq/kg the numbers of