TH1/TH2 imbalance induced by chronic stress exposition is related to different vulnerability to stress effects in BALB/c and C57BL/6 mice.

PALUMBO ML; CANZOBRE MC; RÍOS H; WALD M; GENARO AM

Tandil, Buenos Aires

Congreso; XL Reunión Anual de la Asociación de Farmacología Experimental; 2008

Asociación Argentina de Farmacología Experimental

Stress has been related to cognitive deficit. The hippocampus, a limbic area involved in learning and memory, is particularly sensitive to the stress effects. Cytokines have been shown to affect some behaviours, including effects on sleep, appetite, sexual behavioural, memory and motor activity. Moreover, IL-2, INF-g (TH1-cytokines) and IL-6 (TH2-cytokines) has been implicated in psychiatric disorders. The aim of the present work was to analyze the correlation between the cytokine production and behavioural alteration induced by stress in Th1-biased C57BL/6 and Th2-biased BALB/c mice. We found that BALB/c but not C57BL/6 mice exposed to chronic stress had a poor learning performance respect to control mice. Histological studies showed that the number of neurons and the thickness in the area CA1 y CA3 of hippocampus were lower in stressed BALB/c but not in stressed C57BL/6 mice respect to control.  Moreover, an increase in ROS production was observed in BALB/c but not in C57BL/6 mice under stress. Finally, we found an increase of INF-g and IL-2 in stressed C57BL/6 mice and a decrease of INF-g and an increase of IL-6 in stressed BALB/c mice. These results indicate that BALB/c mice are more vulnerable to stress effects than C57BL/6 mice associated to a differential regulation of TH1/ TH2 cytokine balance.