The effect of gonadectomy and treatment with testosterone on fear behavior in gonadectomized rats.

Effective perception of fear signals is crucial for organism survival. When threated the organism indicated defensive behavior responses that can investigate by using elevated plus–maze. The increas in two parameters of % open arm entries (%OAE) and % time spent in the open arm(%OAT) in the elevated plus – maze were considered as anti –fear effect.In this research the effect of testosterone on fear behavior of gonadectomized rats (GDX), in the elevated plus – maze investigated.. Subcutaneous (SC) injection of different doses of testosterone (100,200,300,450µg /rat) to rats increased % open arm entries (%OAE) and %open arm time spent (%OAT)with dose dependent response manner. Maximum response was obtained with 450µg/rat of the drug (P<0.001).It is concluded that testosterone decreases fear behavior.