The effects of irradiation by 12C carbon ions on monoamine exchange in several rat brain structures

Rats were irradiated with carbon ions (¹²C) in a Nuklotron accelerator. The irradiation dose was 1 Gy, the energy of the ions was 500 MeV/nuclon, and the linear energy transmission (LET) was 10.6 keV/micron. The animals were decapitated 1 day after irradiation. We isolated the prefrontal cortex, nucleus accumbens, hypothalamus, hippocampus, and striatum, where we determined the concentrations of monoamines and their metabolites. Strong changes were observed in three structures, viz., the prefrontal cortex, nucleus accumbens, and hippocampus. However, significant changes were found in the prefrontal cortex and weaker changes were seen in the nucleus accumbens, whereas changes were insignificant in the hippocampus. This reaction may be related to the fact that the animals were examined on the 2nd day after irradiation. It was shown that an increase in the interval between irradiation and examination of animals results in enhancement of the effects of radiation treatment. The experiments revealed the high sensitivity and reactivity of the prefrontal cortex, which we relate to the key role of this structure in vitally critical processes of behavior.