Person: GÖREN, MEHMET ZAFER
Loading...
Email Address
Birth Date
Research Projects
Organizational Units
Job Title
Last Name
GÖREN
First Name
MEHMET ZAFER
Name
3 results
Search Results
Now showing 1 - 3 of 3
Publication Open Access The behavioral and neurochemical effects of methylprednisolone or metyrapone in a post-traumatic stress disorder rat model(KARE PUBL, 2019) AYDIN OMAY, BANU; Tanriverdi, Ayse Melek; Aydin, Banu; Bebitoglu, Berna Terzioglu; Cabadak, Hulya; Goren, M. ZaferOBJECTIVE: Mechanisms contributing to the post-traumatic stress disorder (PTSD) that involve several physiological sys- tems, and the activation of the hypothalamic-pituitary-adrenal axis (HPA) is one of the most known systems in the PTSD pathophysiology. The present study investigates the potential effects of methylprednisolone, metyrapone and their association with the noradrenergic system within the rostral pons, a region containing the locus coeruleus (LC) in a rat model of PTSD induced with predator scent. METHODS: In this study, Sprague-Dawley rats were exposed to the stress by exposure to the scent of dirty cat litter, which is a natural stressor of a predator. One week later, the rats were re-exposed to a situational reminder (clean cat litter). The rats were treated using either methylprednisolone, metyrapone or physiological saline before exposure to a situational reminder (n=8 in each group). Noradrenaline (NA) levels in the rostral pons homogenates were analysed using ELISA. RESULTS: The anxiety indices of the rats exposed to the trauma were found to be significantly higher than the anxiety indices of the control rats. Metyrapone produced a significant increase in the anxiety indices of the non-stressed rats, and methylprednisolone did not produce a change in the anxiety indices of the non-stressed rats. Methylprednisolone treatment suppressed the anxiety in the stressed rats. Metyrapone treatment increased the anxiety indices in the stressed rats but still being lower than that of the saline-treated stressed rats. Significant decrease in the freezing time was observed following the methylprednisolone treatment both in the stressed and non-stressed rats. NA content in the rostral pons of the stressed rats was significantly higher than that of the non-stressed rats. Methylprednisolone or metyrapone treatments decreased the NA content in the non-stressed rats as compared to the saline treatment. However, these decreases were not significant. CONCLUSION: In this study, findings suggest that stress may give rise to endocrine, autonomic and behavioural responses. The anxiety indices and NA levels in the rostral pons increased with the traumatic event. The methylprednisolone treatment may suppress anxiety through interactions between the LC and the HPA axis.Publication Metadata only D-Cycloserine acts via increasing the GluN1 protein expressions in the frontal cortex and decreases the avoidance and risk assessment behaviors in a rat traumatic stress model(ELSEVIER SCIENCE BV, 2015) CABADAK, HÜLYA; Saridogan, Gokce Elif; Aykac, Asli; Cabadak, Hulya; Cerit, Cem; Caliskan, Mecit; Goren, M. ZaferD-cycloserine (DCS), an FDA approved anti-tuberculosis drug has extensively been studied for its cognitive enhancer effects in psychiatric disorders. DCS may enhance the effects of fear extinction trainings in animals during exposure therapy and hence we investigated the effects of DCS on distinct behavioral parameters in a predator odor stress model and tested the optimal duration for repeated daily administrations of the agent. Cat fur odor blocks were used to produce stress and avoidance and risk assessment behavioral parameters were used where DCS or saline were used as treatments in adjunct to extinction trainings. We observed that DCS facilitated extinction training by providing further extinction of avoidance responses, risk assessment behaviors and increased the contact with the cue in a setting where DCS was administered before extinction trainings for 3 days without producing a significant tolerance. In amygdala and hippocampus, GluN1 protein expressions decreased 72 h after the fear conditioning in the traumatic stress group suggesting a possible down-regulation of NMDARs. We observed that extinction learning increased GluN1 proteins both in the amygdaloid complex and the dorsal hippocampus of the rats receiving extinction training or extinction training with DCS. Our findings also indicate that DCS with extinction training increased GluN1 protein levels in the frontal cortex. We may suggest that action of DCS relies on enhancement of the consolidation of fear extinction in the frontal cortex. (C) 2015 Elsevier B.V. All rights reserved.Publication Metadata only The change in muscarinic receptor subtypes in different brain regions of rats treated with fluoxetine or propranolol in a model of post-traumatic stress disorder(ELSEVIER SCIENCE BV, 2012) AYDIN OMAY, BANU; Aykac, Asli; Aydin, Banu; Cabadak, Hulya; Goren, M. ZaferThis study shows the possible contribution of muscarinic receptors in the pathophysiology of post-traumatic stress disorder. Sprague-Dawley rats of both sexes were exposed to dirty cat litter (trauma) for 10 min and the protocol was repeated 1 week later with a trauma reminder (clean litter). The rats also received intraperitoneal fluoxetine (2.5, 5 or 10 mg/kg/day), propranolol (10 mg/kg/day) or saline for 7 days between two exposure sessions. Functional behavioral experiments were performed using elevated plus maze, following exposure to trauma reminder. Western blot analyses for M-1, M-2, M-3, M-4 and M-5 receptor proteins were employed in the homogenates of the hippocampus, the frontal cortex and the amygdaloid complex. The anxiety indices increased from 0.63 +/- 0.02 to 0.89 +/- 0.04 in rats exposed to the trauma reminder. The freezing times were also recorded as 47 +/- 6 and 133 +/- 12 s, in control and test animals respectively. Fluoxetine or propranolol treatments restored the increases in the anxiety indices and the freezing times. Female rats had higher anxiety indices compared to males. Western blot data showed increases in M-2 and M-5 expression in the frontal cortex. Expression of M-1 receptors increased and M-4 subtype decreased in the hippocampus. In the amygdaloid complex of rats, we also detected a down-regulation of M-4 receptors. Fluoxetine and propranolol only corrected the changes occurred in the frontal cortex. These results may imply that muscarinic receptors are involved in this experimental model of post-traumatic stress disorder. (C) 2012 Elsevier B.V. All rights reserved.