The influence of experimentally changed thyroid status on cognitive activity and angiogenesis in brain of female of inbred mice С3 Н-А

The study was performed using 33 virgin females of inbred mice C3H-A. The animals were randomized as follows 3:2:2. The first group was hyperthyroid (n1=15), the second hypothyroid (n2=10) and the third euthyroid (control) (n3=8). The results of individual behavior investigation as to 18 and 40 weeks of our experiment in “open field” test clarified that quantitative traces of almost whole components of cognitive activity was much higher in hyperthyroid mice as compared to other groups (control and hypothyroid ones). The cognitive behavior activity has gradually been decreasing in hypothyroid group especially in connection to burrow reflex. As to those elements of behavior which are of characteristics of emotions the results were a bit different. The emotional characteristics were more expressed in hyperthyroid group as compared to control and hypothyroid ones. The immunohistochemical investigations clearly showed that expression of vascular endothelial growth factor (VEGF) in neocortex and hyppocampus prevails in hyperthyroid mice and less expressed in animals deprived of thyroid hormones (p < 0.05). The level of glial fibrillar acidic protein (GFAP) expression was significantly lower in brain of hypothyroid animals (p < 0.05). Otherwise the level of platelet derived growth factor receptor-α (PDGF-Rα) expression was much higher in brain of hypothyroid mice (p < 0.05). Our results presented for this paper confirmed the key role of thyroid hormones in regulation of cell interaction not only for developing neural cells but also for adult central nerve system.