Relevance of the topic: the brain is the organ with the highest sensitivity to thyroid hormone deficiency in the body. Detection of autoantibodies to neurotransmitter receptors helps in the early diagnosis of neurodegenerative processes and thus in explaining changes in brain function and mental disorders in hypothyroidism. Purpose of the research: in experimental hypothyroidism serum glutamate receptor (Glu-R), dopamine receptor (DA-R), GABA-receptor (GABA-R), opiate receptors (m-OR), serotonin receptor (Ser-R), acetylcholine receptor ( Chol-R) and b-endorphin (b-end) to determine the effect of L-thyroxine and neuroprotectors on changes in autoantibodies. Materials and Methods: To achieve the goal in the study, the condition of hypothyroidism was modeled by injecting mercazolyl at a dose of 2.5 mg / 100 g into the stomach of 21 white rats for 21 days. The animals were divided into 6 groups: Group I - intact; Group II - 21-day hypothyroidism, Group III - 30-day hypothyroidism, Group IV - rats with hypothyroidism treated with L-thyroxine, Group V - L-thyroxine and rats treated with "neuromac", Group VI - L-thyroxine and " somazina ”treated hypothyroid rats. pharmacotherapy was carried out for 10 days. The amount of autoantibodies to Glu-R, DA-R, GABA-R, m-OR, Ser-R, Chol-R and b-end in the serum of rats was determined by the method of immunoenzyme analysis "ELI-N-Test" (Russia). Serum levels of T3, T4 and TTG hormones, body weight and temperature were determined. The figures were statistically processed. Results: In experimental hypothyroidism, the amount of autoantibodies to neurotransmitter receptors increased reliably relative to intact group values on day 21 (group II) and day 30 (group III). Decreased levels of autoantibodies were found in the serum of treated animals. At the same time, L-thyroxine was more effective when used with neuroprotectants. Conclusion: our study has been showed that an increase in the number of autoantibodies to neurotransmitter receptors indicates pathogenetic changes in immune system function, cognitive impairment and neurodegenerative processes in hypothyroidism, and it is advisable to use a neuroprotective drug in combination with L-thyroxine to correct these changes.

Index Terms- hypothyroidism, cerebral, serum, Glu-R, DA-R, GABA-R, m-OR, Ser-R, Chol-R, b-end, neurotropic autoantibodies.