title: Combined effects of antiorthostatic suspension and ionizing radiation on the behaviour and neurotransmitters changes in different brain structures of rats.
abstract: Space flight factors (SFF) significantly affect the operating activity of astronauts during deep space missions. In contrast to an orbital flight, leaving the Earth's magnetic field is fraught with the dangers of exposure to ionizing radiation and more specifically, the high-energy nuclei component of galactic cosmic rays. Microgravity, just another critical non-radiation factor, significantly affects the normal functioning of the CNS. Some morphological structures of the brain, such as the prefrontal cortex and the hippocampus, that are rich in monoaminergic and acetylcholinergic neurones, are the most sensitive to the effects of ionizing radiation and non-radiation spaceflight factors (SFF). In this work we have studied the combined effects of microgravity (in antiorthostatic suspension model, AS) and irradiation (γ-ray and protons in spread-out Bragg peak) on the behaviour, cognitive abilities, and metabolism of monoamines and acetylcholine in the key structures of the rat's brain. Irradiation (as independently as combined with AS) resulted in the decrease of thigmotaxis in rats. Learning problems, caused by the malfunctioning of the working memory but not the spatial memory, were observed in response to AS as well as to the SFF in combination. Analysis of monoamines metabolism showed that the serotoninergic system was the most affected by the SFF. Concentration of acetylcholine in the hippocampus significantly increased in the groups of irradiated rats, and in the groups which were exposed to the SFF in combination, compared to the rats exposed only to AS.
authors: Laboratory of Extreme Physiology, Institute of Medico-Biological Problems RAS, Moscow, Russia. Electronic address: viktor_kohan@hotmail.com.
authors: V S
authors: VS
authors: Kokhan
authors: Laboratory of Extreme Physiology, Institute of Medico-Biological Problems RAS, Moscow, Russia.
authors: M I
authors: MI
authors: Matveeva
authors: Institute of Higher Nervous Activity and Neurophysiology RAS, Moscow, Russia.
authors: A S
authors: AS
authors: Bazyan
authors: Zakusov Institute of Pharmacology RAMS, Moscow, Russia.
authors: V S
authors: VS
authors: Kudrin
authors: Institute of Physiologically Active Compounds RAS, Chernogolovka, Russia.
authors: A
authors: A
authors: Mukhametov
authors: Laboratory of Extreme Physiology, Institute of Medico-Biological Problems RAS, Moscow, Russia.
authors: A S
authors: AS
authors: Shtemberg
mesh_terms: D000818:Animals; D001362:Avoidance Learning / Q000502:physiology / Q000528:radiation effects; D001522:Behavior, Animal / Q000502:physiology / Q000528:radiation effects*; D001921:Brain / Q000378:metabolism* / Q000528:radiation effects*; D005106:Exploratory Behavior / Q000528:radiation effects; D006112:Gravitation; D008297:Male; D018782:Maze Learning / Q000502:physiology / Q000528:radiation effects; D018377:Neurotransmitter Agents / Q000378:metabolism*; D011839:Radiation, Ionizing; D051381:Rats; D017208:Rats, Wistar; D013026:Space Flight; D013997:Time Factors
chemical_list: D018377:Neurotransmitter Agents
keywords: Antiorthostatic suspension; CNS risks; Cognition; Ionizing radiation; Neurotransmitters changes