Saffron (Crocus sativus) aqueous extract reverses the hypothalamus-pituitary-adrenal axis activity in rat model of post-traumatic stress disorder

Abstract Crocus sativus L., Iridaceae, has been used worldwide in traditional medicinefor treatment ofsome neurological disorderssuch as depression. Post-traumatic stress disorder is a mental disorder developed in peoplewho experience stressful events. Since stress has been proposed tocause thehypothalamic-pituitary-adrenal axis malfunction in post-traumatic stress disorder patients, this study aimed at investigating the effect of saffron aqueous extract on hypothalamic-pituitary-adrenal axis activity in rats of post-traumatic stress disorder model. Here, Post-traumatic stress disorder animals received an acute electro foot shock; however, 5 min before the stress session, these animals received an intra-cerebral-ventricular (10 µg/rat) infusion of either saffron aqueous extract or saline. Twenty one days later, they were re-exposedto the stress box withoutinducing stress, andthen were examined for their freezing behavior. The impact of stress and saffron aqueous extract on serum corticosterone, corticotrophin releasing hormone gene expression in hypothalamus and glucocorticoid receptor gene expression in pituitary gland werethen evaluated on day 28. Intra-cerebral-ventricular injection of saffron aqueous extract resulted in an increase in serum corticosterone level and reduced symptoms of freezing behavior, and corticotrophin releasing hormone and glucocorticoid receptor gene expression in post-traumatic stress disorder groups.Saffron administration could improve the symptoms of stress-induced post-traumatic stress disorder, possiblythrough the adjustment ofhypothalamic-pituitary-adrenal axis function.

Panic-like behaviors in Carioca High-and Low-conditioned Freezing rats

Panic disorder involves both recurrent unexpected panic attacks and persistent concern about having additional attacks. Electrical stimulation of the dorsal periaqueductal gray (dPAG) is an animal model of both panic attack and panic disorder, whereas contextual fear conditioning represents a model of anticipatory anxiety. Previous research indicated that anxiety has an inhibitory effect on panic attack-like behavior. However, still unclear is the role that anticipatory anxiety plays in panic disorder-like behaviors. This issue was investigated with two lines of animals selectively bred for high (Carioca High-Freezing) and low (Carioca Low-Freezing) freezing in response to contextual cues associated with footshock. The results suggest that although anticipatory anxiety might exert an inhibitory effect on the expression of panic attack, it might also facilitate the pathogenesis of panic disorder.

Effects of Auditory Environment on Freezing Behavior of Mice in a Novel Context

Freezing behavior is a widely used parameter that represents the level of fear. A number of studies on emotional learning have used this behavior for quantification of fear that results from a cue or a context. Even though the expression of freezing behavior is based on the dynamic interaction of mice with the environment, the effect of environmental stimuli on freezing behavior has not been studied extensively because of its minority compared to the effect of conditioning-stimuli. In this study, we found that the auditory environment of a context affects the freezing behavior of a mouse in it. This effect was not observed when the mouse was exposed to the context for the first time. However, during the second exposure, the level of freezing behavior increased significantly in an intensity-dependent manner, while the type, pitch, and rhythm of additional sounds involved in the context did not induce notable effects. This intensity-dependent effect was unrelated to the level of fear and anxiety, reflecting another aspect of the freezing behavior as a parameter for recognizing the pattern of normal behaviors.