FORMATION OF PROTECTIVE BEHAVIOR OF YOUNG RATS IN CONDITIONS OF THYROID DYSFUNCTION
Keywords:experimental hyper-/hypothyroidism, anxiety, acquired and congenital behavior, GABA, serotonin, glutamate, glycine
Thyroid dysfunction is accompanied by the psychoemotional body status disorders. The pathogenesis of these disorders requires in-depth study. The aim of studying the neurotransmitter mechanism of the cognitive activity of young rats under conditions of thyroid dysfunction, which can be the basis for the development of methods for correcting the psychoemotional component of these pathologies.
Materials and methods. Behavioral activity was investigated in an elevated plus maze and in the Polsort test; the formation of spatial memory was studied in the Morris water maze, and in the 8-arm food maze. The content of glycine, gamma-aminobutyric acid (GABA), glutamate, serotonin in neocortex and hippocampus were determined chromatographically.
Results. Under conditions of experimental hyperthyroidism, young rats showed increasing the number of transitions to the plus maze open arms by 88 % and their duration of stay there by 2.3 times, and also acceleration of the appearance of the first physical activity in the Polsort test by 21 %. The anxiety decrease and the spatial memory optimization in rats were accompanied by the significant increase in contents of cortical GABA (51 %), hippocampal glutamate (25 %), and cortical and hippocampal serotonin (25–33 %). It was found that the depressive-like state is formed under conditions of experimental hypothyroidism, which is reflected in a significant increasing in 4.2-fold in the duration of the first fading, as well as the time for the onset of motor activity in the Paulsort test by 32 %. The anxiogenic effect is accompanied by the latent period lengthening (22 %) for defensive reactions in the Morris maze. Cognitive and behavioral deficits were characterized by the absence of GABA accumulation while increasing cortical serotonin level (37 %), and significantly increasing hippocampal glutamate content (43 %).
Conclusions. In hyperthyroidism, the indicated GABA content increase against the background of hippocampal glutamate content augment provides an anxiolytic effect and support for the mnestic activity of rats, but in hypothyroidism, the excessive growth of hippocampal glutamate content with cortical serotonin content increase in the absence of GABA accumulation causes an excitotoxic effect and is accompanied by forming depressive-like state and deteriorating spatial memory.
Dwyer JB, Aftab A, Radhakrishnan R, et al. Am J Psychiatry 2020;177(8): 686-705. https://doi.org/10.1176/appi.ajp.2020.19080848.
Pelúcio L, Nardi AE, Ornelas AC, Levitan M. J Depression Anxiety 2016;5(3): 1-7. https://doi.org/10.4172/2167-1044.1000241
Chaalal A, Poirier R, Blum D, et al. Mol Neurobiol 2019;56(1): 722-735. https://doi.org/10.1007/s12035-018-1111-z
Stepien BK, Huttner WB. Front Endocrinol (Lausanne) 2019;10: 209. https://doi.org/10.3389/fendo.2019.00209
Bavarsad K, Hosseini M, Hadjzadeh M, Sahebkar A. J Cell Physiol 2019;234(9): 14633-14640. https://doi.org/10.1002/jcp.28198
Fischer S, Ehlert U. Depress Anxiety 2018;35(1): 98-110. https://doi.org/10.1002/da.22692
Zhong S, Chen G, Zhao L, et al. Neuroendocrinology 2019;108(3): 232-243. https://doi.org/10.1159/000497182
Umezu T, Kita T, Morita M. Toxicol Rep 2019;6: 1031-1039. https://doi.org/10.1016/j.toxrep.2019.10.005
Schiera G, Di Liegro CM, Di Liegro I. Cancers 2021;13: 2693. https://doi.org/10.3390/cancers13112693
Calissendorff J, Falhammar H. Medicina (Kaunas) 2020;56(1): 40. https://doi.org/10.3390/medicina56010040
Lucia F, Pacheco-Torres J, González-Granero S, et al. Front Neuroanat 2018;12. https://doi.org/10.3389/fnana.2018.00031
Voronkov AV, Shabanova NB, Pozdnyakov DI, et al. Sovremen Probl Nauki i Obrazovaniya 2017;(5): 28-35.
Kochkin NV, Kulikov VA, Zavyalov EL, et al. Vavilov J Genet Breeding 2015;19(4): 388-393. https://doi.org/10.18699/vj15.049.
Chekman IS, Bielenichev ІF, Nahorna ОO, Garchakova NO. Doklinichne vyvchennja specyfichnoi' aktyvnosti potencijnyh likars'kyh zasobiv pervynnoi' ta vtorynnoi' nejroprotekcii', Kyiv, 2016: 80 p.
Kokunin VA. Ukr Bioсhem J 1975;47(6): 776-791.
Rodyns'kyj OG, Bogdanova OO. Zagal'na Patologija ta Patologichna Fiziologija 2012;1: 35-42.
Musaev AT, Kisebayev ZS, Alishev OK, et al. Mezhdunar Zhurn Prikladnyh i Fundam Issled 2017;1(1): 52-57.