Verificação da participação do hipocampo ventral e dorsal nas respostas comportamentais exibidas no labirinto em cruz elevado (LCE)

Abstract

The control of the emotion is carried out by the limbic system, a complex system, wich envolve a structures such as the hippocampus, hypothalamus, frontal cortex, among others. Fear is an important emotion in the adaptive process, because it prepares the organism when there is an iminent danger through of fight or flight reaction. Stress and anxiety are related to fear and the anxiety is the description of fear without stimuli, or when it exhists, there is a bad adaptive answer, making it inadequate or constant and persistent. These stressors events change the brain homeostasis, producing consequences in the organism, leading the phatological anxiety with somatics manifestation, psychic and behavioral. The hippocampus is one of the targets of deleterious effects caused by the stress and anxiety, performing its study important. This work had the objective to evaluate the participation of dorsal hippocampus and ventral hippocampus in the modulation of the defensives behavior in mice exposed to elevated plus maze (EPM), through the use of the microinjection of cobalto chloride, wich inhibits brain área microinjected: ventral hippocampus (VH) or dorsal hippocampus (DH). Defensive behavioral response in mice exposed to EPM were assesssed. Results showed that treatment with cobalto chloride in the VH significative increased the % of time in animals into the open arm and also increased frequency of entries into the same amrs. Regarding complementary measures, animals performed less stretched attend posture (SAP) in the pçrotected area and increased the number of arrival at the open arm endof in comparison to control group. Therefore, this study demonstrated participation of the ventral hippocampus in the anxiety-like behaviors in the EPM, but not dorsal hippocampus.