Mehmet BERKÖZ, Fatma Rezan HATUNGİL, Ali Erdinç YALIN, Ülkü ÇÖMELEKOĞLU, Serap YALIN, Hüseyin BEYDAĞI, Bora REŞİTOĞLU, Nefise Özlen ŞAHİN, Pelin EROĞLU

Stres ve menopozun öğrenme üzerindeki etkileri

Amaç: Bu çalışmada stres ve menopozun birlikte, öğrenme işlevi üzerindeki etkileri araştırılmıştır. Yöntem: Çalışmada, 60 adet dişi Wistar-Albino sıçan kullanılmıştır. Bu sıçanlar randomize olarak kontrol (Grup I), deneysel immobilizasyon stres modeli (Grup II), deneysel menopoz modeli (Grup III) ve deneysel menopoz modeli + deneysel stres modeli (Grup IV) olmak üzere her bir grupta 15’er hayvan bulunan 4 gruba ayrılmıştır. Tüm sıçanların uzun dönemdeki bilişsel ve motor yetileri davranış deneyleri (açık alan ve Morris su tankı) ile değerlendirilmiştir. Ayrıca hipotalamus-hipofiz-adrenal ekseninin geribildirim işlevinde merkezi konumunda olan kortikosteroid reseptör (Glukokortikoid reseptörü ve mineralokortikoid reseptörü) gen ekspresyonu mRNA izolasyonu ve cDNA sentezi takibinde SYBR Green kullanılarak eş zamanlı PCR yöntemiyle incelenmiştir. Bulgular: Tüm grupların kendi içinde günlere göre ortalama yükseltiyi bulma sürelerinin karşılaştırmasında, birinci günden 4. güne kadar, tüm gruplarda her günün ortalama yükseltiyi bulma sürelerinin bir önceki günden istatistiksel olarak anlamlı düzeyde kısa olduğu saptanmıştır (p<0.001). Güne göre yükseltiyi bulma sürelerinin gruplar arasında karşılaştırmasında istatistiksel olarak anlamlı bir fark saptanmamıştır (p>0.05). Açık alan deneyinde ortalama katedilen mesafenin gruplara göre karşılaştırmasında grup II en düşük ortalamaya sahip olmasına karşın, gruplar arasında istatistiksel olarak anlamlı bir fark bulunamamıştır (p>0.05). Hipokampal dokuda hem glukokortikoid reseptörünün hem de mineralokortikoid reseptörünün gen ekspresyonu tüm gruplarda kontrol grubuna kıyasla düşük bulunmuştur. Ancak bu düşüş istatistiksel olarak anlamlı bulunamamıştır (p>0.05). Sonuç: Bu sonuç akut immobilizasyon stresin ve deneysel menopoz modelinin öğrenme üzerinde etkili olmadığını düşündürmüştür.

Anahtar Kelimeler:

Stres, menopoz, öğrenme, hipotalamus-hipofiz-adrenal aksı, kortikosteroid reseptörleri

The effects of stress and menopause on learning

Aim: In this study, we aimed to to investigate the co-effect of stress and menopause on the learning ability in rats. Methods: 60 female Wistar-Albino rats were used in this study and were randomly divided into four groups (15 rats per group) as follows: Control group (Group I), experimental immobilization stress model (Group II), experimental menopause model (Group III), and experimental menopause model + experimental stress model (Group IV). Long-term cognitive and motor abilities of all rats were evaluated by conducting behaviour experiments (open field and morris water maze test). Furthermore, the gene expression of corticosteroid receptor (glucocorticoid receptor and mineralocorticoid receptor) was examined by Real-Time PCR using SYBR Green followed by mRNA isolation and cDNA synthesis. Results: In the comparison study of in-group time for attaining mean elevation over days, it was detected that time for attaining mean elevation was statistically significantly shorter than previous day from 1st day to 4th(p<0.001). There was no statistically significance for daily time for mean elevation among the groups (p>0.05). In the open area experiment, although the Group II exhibited shorter mean when comparing the progressed distances, but the difference among the groups was not statistically significant (p>0.05). Gene expression of both glucocorticoid receptor and mineralocorticoid receptor in the hipocampal tissue was determined to be lower in comparison with the control group. However, this decrease was not statistically significant (p>0.05). Conclusion: This result shows that acute immobilization stres and experimental menopause model is not efficient on the learning ability in rats.

Keywords:

Stress, menopause, learning, hypothalamus-pituitary-adrenal axis,

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