Increase in the Number of Cb1 Immunopositive Neurons in the Amygdaloid Body after Acute Cold Stress Exposure

PURPOSE: According literature data the animal's response to stress depends not only upon the state and conditions of the animal but also upon the nature of the stressor itself. It is known that stress have wideranging effects on neuroendocrine, autonomic, immune, and hormonal function. Different research groups have shown induction of acute physical stress by low temperature exposure which have been reported to impair motor activity, modulate pain perception, anxiety and depression-like behaviors in the animals. Considerable work has established the amygdaloid body as a key site involved in the generation of fear and anxiety responses, the assignment of emotional salience to external stimuli, the coordination of affective, autonomic, and behavioral responses. The aim of our study was to examine the effect of cold stress on density of CB1 receptors in the amygdaloid body. METHODS: Immunocytochemistry and morphometric analysis were used to determined density of CB1 immunopositive neurons in the amygdaloid body of male Wistar rats exposed to acute cold stress. RESULTS: Our morphometric studies reveal that cold stress significantly increased (around 40 %) density of CB1 immunopositive neurons in the rat amygdaloid body compared with control group. CONCLUSIONS: Our results confirm that temperature fluctuation induces stress and endocanabinoid