Proceedings of the International scientific and practical conference ―Science at the Frontier of Progress‖ (January 27-29, 2026) / Publisher website: www.naukainfo.com. – Paris, France, 2026. - 302 p.

115 neurotransmitter systems in the regulation of psychoemotional activity under experimentally induced hypothyroidism. Thus, an emotional state accompanied by increased activity of the brain noradrenergic system altered the direction of regulatory mechanisms involved in anxiety formation, reversing the anxiogenic effects caused by thyroid hormone hypofunction, particularly through serotonergic and glutamatergic pathways. Conclusions. Hypothyroidism during early ontogenesis induces significant disturbances in emotional and locomotor activity, reducing the adaptive capacity of the brain. Emotional stress exposure on the background of hypothyroidism partially compensates for the negative influence of serotonergic and glutamatergic systems on emotional regulation, leading to reduced anxiety and anxiogenic behavior. However, the exclusion of GABAergic and glycinergic systems as stress-limiting regulatory mechanisms, together with glutamate accumulation in the hippocampus, indicates progressive depletion of adaptive reserves of the central nervous system in juvenile animals under experimental hypothyroidism.