title: Exposure to (12)C particles alters the normal dynamics of brain monoamine metabolism and behaviour in rats.
abstract: Planning of the deep-space exploration missions raises a number of questions on the radiation protection of astronauts. One of the medical concerns is associated with exposure of a crew to highly energetic particles of galactic cosmic rays. Among many other health disorders, irradiation with these particles has a substantial impact on the central nervous system (CNS). Although radiation damage to CNS has been addressed extensively during the last years, the mechanisms underlying observed impairments remain mostly unknown. The present study reveals neurochemical and behavioural alterations induced in rats by 1Gy of 500MeV/u (12)C particles with a relatively moderate linear energy transfer (10.6keV/μm). It is found that exposure to carbon ions leads to significant modification of the normal monoamine metabolism dynamics as well as the locomotor, exploratory, and anxiety-like behaviours during a two-month period. The obtained results indicate an abnormal redistribution of monoamines and their metabolites in different brain regions after exposure. The most pronounced impairments are detected in the prefrontal cortex, nucleus accumbens, and hypothalamus that illustrate the sensitivity of these brain regions to densely ionizing radiations. It is also shown that exposure to (12)C particles enhances the anxiety in animals and accelerates the age-related reduction in their exploratory capability. The observed monoamine metabolism pattern may indicate the presence of certain compensatory mechanisms being induced in response to irradiation and capable of partial restoration of monoaminergic systems' functions. Overall, these findings support a possibility of CNS damage by space-born particles of a relatively moderate linear energy transfer.
authors.affiliation: Laboratory of Radiation Biology, Joint Institute for Nuclear Research, 6 Joliot-Curie St., 141980 Dubna, Moscow Region, Russia; Biophysics Department, "Dubna" University, 19 Universitetskaya St., 141980 Dubna, Moscow Region, Russia. Electronic address: dem@jinr.ru.
authors.forename: Oleg V
authors.initials: OV
authors.lastname: Belov
authors.affiliation: Laboratory of Radiation Biology, Joint Institute for Nuclear Research, 6 Joliot-Curie St., 141980 Dubna, Moscow Region, Russia; Academy of Sciences of Moldova, Chișinău, Moldova.
authors.forename: Ksenia V
authors.initials: KV
authors.lastname: Belokopytova
authors.affiliation: Institute of Higher Nervous Activity and Neurophysiology, Russian Academy of Sciences, Moscow, Russia.
authors.forename: Ara S
authors.initials: AS
authors.lastname: Bazyan
authors.affiliation: Zakusov Institute of Pharmacology, Moscow, Russia.
authors.forename: Vladimir S
authors.initials: VS
authors.lastname: Kudrin
authors.affiliation: Zakusov Institute of Pharmacology, Moscow, Russia.
authors.forename: Viktor B
authors.initials: VB
authors.lastname: Narkevich
authors.affiliation: Laboratory of Radiation Biology, Joint Institute for Nuclear Research, 6 Joliot-Curie St., 141980 Dubna, Moscow Region, Russia; Institute of Biomedical Problems, Russian Academy of Sciences, Moscow, Russia.
authors.forename: Aleksandr A
authors.initials: AA
authors.lastname: Ivanov
authors.affiliation: Laboratory of Radiation Biology, Joint Institute for Nuclear Research, 6 Joliot-Curie St., 141980 Dubna, Moscow Region, Russia.
authors.forename: Yury S
authors.initials: YS
authors.lastname: Severiukhin
authors.affiliation: Laboratory of Radiation Biology, Joint Institute for Nuclear Research, 6 Joliot-Curie St., 141980 Dubna, Moscow Region, Russia.
authors.forename: Gennady N
authors.initials: GN
authors.lastname: Timoshenko
authors.affiliation: Laboratory of Radiation Biology, Joint Institute for Nuclear Research, 6 Joliot-Curie St., 141980 Dubna, Moscow Region, Russia.
authors.forename: Eugene A
authors.initials: EA
authors.lastname: Krasavin
mesh_terms: D000588:Amines / Q000378:metabolism*; D000818:Animals; D001522:Behavior, Animal; D001921:Brain / Q000378:metabolism* / Q000528:radiation effects; D002244:Carbon / Q000737:chemistry*; D003359:Cosmic Radiation; D004307:Dose-Response Relationship, Radiation; D007031:Hypothalamus / Q000528:radiation effects; D007477:Ions; D018499:Linear Energy Transfer; D008297:Male; D009714:Nucleus Accumbens / Q000528:radiation effects; D017397:Prefrontal Cortex / Q000528:radiation effects; D011829:Radiation Dosage; D011832:Radiation Injuries; D011835:Radiation Protection / Q000379:methods*; D011839:Radiation, Ionizing; D051381:Rats; D017207:Rats, Sprague-Dawley; D013026:Space Flight
chemical_list: D000588:Amines; D007477:Ions; D002244:Carbon
keywords: Behaviour; Brain neuromediators; Galactic cosmic rays; Monoamine metabolism