Transmission of stress between cagemates: a study in rats.

The neuroendocrine responses triggered by stressors cause significant behavioral changes in animals. Considering the continuous behavioral interaction between social animals, it would be reasonable to suggest that the aforementioned behavioral changes can lead to transmission of stress between individuals. In the present study the aim is to investigate the outcomes of the behavioral interaction between stressed and unstressed animals housed together. A total of 28 adult male Wistar rats were used in the study. The animals were randomly allocated to four groups. Two of the groups were exposed to white noise stress in a period of 15 days, while the other two groups remained unstressed. One of the stress exposed groups served as the stress control (SC) group and one of the non-stressed groups served as the reference value (RV) group. The remaining two groups were transmission groups. Every two animals of the non-stressed transmission group (TC) have been housed with two other animals of the stress exposed transmission group (TS) during the experimental period. After the stress exposure period, six animals from each group were subjected to behavioral assessment in an elevated plus maze (EPM), and subsequently, their cortisol levels were determined

Chronic continuous perfusion of the hibernation triggering opioid DADLE did not cause any major physiological alterations in rats

[D-Ala(2), D-Leu(5)] enkephalin (DADLE), a delta opioid receptor agonist, can induce mammalian hibernation and has hibernation-like effects in non-hibernating species. It has also been demonstrated that DADLE has protective efficacy on various tissues such as nervous, cardiac, and hepatic tissues. Despite substantial research conducted in the last decade about the tissue protective efficacy of DADLE, detailed underlying mechanisms have not been fully elucidated. In the present study we investigated in a rat model whether continuous perfusion of DADLE can induce potentially tissue protective alterations in physiological parameters. In the study 48 young male Wistar rats were used. They were divided into control and experimental groups, each group consisting of 24 animals. DADLE was perfused to experimental group rats continuously for 28 days using subcutaneously implanted osmotic mini-pumps. We investigated its effects on body temperature, antioxidant protection [total antioxidant capacity (TAC), ascorbic acid (AA), and malondialdehyde (MDA) levels], white blood cell (WBC) count, and coagulation parameters [activated partial thromboplastin time (APTT), prothrombin time (PT), thrombin time (TT)]. While thrombin time was significantly lengthened in the DADLE treated group, there were no statistically significant differences in the other investigated parameters between the experimental group and the control group

Transmission of stress between cagemates: A study in rats

The neuroendocrine responses triggered by stressors cause significant behavioral changes in animals. Considering the continuous behavioral interaction between social animals, it would be reasonable to suggest that the aforementioned behavioral changes can lead to transmission of stress between individuals. In the present study the aim is to investigate the outcomes of the behavioral interaction between stressed and unstressed animals housed together. A total of 28 adult male Wistar rats were used in the study. The animals were randomly allocated to four groups. Two of the groups were exposed to white noise stress in a period of 15 days, while the other two groups remained unstressed. One of the stress exposed groups served as the stress control (SC) group and one of the non-stressed groups served as the reference value (RV) group. The remaining two groups were transmission groups. Every two animals of the non-stressed transmission group (TC) have been housed with two other animals of the stress exposed transmission group (TS) during the experimental period. After the stress exposure period, six animals from each group were subjected to behavioral assessment in an elevated plus maze (EPM), and subsequently, their cortisol levels were determined

Effects of cryopreservation and leukodepletion on morphological index of red blood cells in dogs

Preservation of blood components for transfusion is a long-standing phenomenon. However, studies of cryopreservation of leukodepleted canine erythrocytes are quite limited and no studies are available with respect to morphological evaluation of erythrocytes during the cryopreservation process. The aim of this study was to determine morphological changes caused by cryopreservation, storage and leukocyte filtration. Healthy adult dogs meeting the criteria for blood transfusion were used in this study. Packed red blood cells (pRBCs) were obtained from each dog. The samples were divided into two groups. Leukocyte filtration was performed on one group of pRBCs. The other group received no filtration. The samples of each group were then allocated into three sub-groups according to storage period and subjected to glycerolization (40% w/v Glycerol) prior to cryopreservation except for day 0 group. Glycerolized samples were stored at -80 degrees C for four and six months. Blood smears were obtained from the samples of day 0 and those thawed and deglycerolized at the end of the storage period. The smears were morphologically evaluated by light microscopy, and Morphological Index (MI) was calculated. MI values of the non-leukodepleted (nLD) and leukodepleted groups (LD) increased from 0.083 and 0.119 to 0.238 and 0.273, respectively. In conclusion, leukocyte filtration did not have impact on the MI values of leukofiltrated and glycerolized pRBC samples but the cryopreservation and storage period did

The Serologic and Molecular Prevalence of Heartworm Disease in Shelter Dogs in the Thrace Region of Turkey

Dirofilaria immitis is an important nematode of dogs and cats which causes fatal heartworm disease in their hosts. The aim of this study was to investigate the prevalence of D. immitis by serologic and molecular methods in shelter dogs, in the Thrace Region of Turkey. Blood samples were collected from 402 dogs in shelters which were located in four cities (Istanbul, Edirne, Tekirdag and Kirklareli) in this region. The blood smears were examined for the presence of D. immitis microfilariae under the light microscope. The commercial Snap3Dx test kit and PCR assay for amplifying the ITS-2 gene region were used for the serological and molecular analyses, respectively. The serologic and molecular prevalence of D. immitis was determined as 6.7% and 2.7%, respectively. D. immitis microfilariae were also determined in the blood smears of three dogs (0.8%). The distribution of the infection according to the provinces was 14.7% in Edirne, 11% in Kirklareli, 1% in Tekirdag and 0% in Istanbul. The occult infection rate was determined as 59.3%. This study revealed the presence of D. immitis for the first time in the Thrace Region of Turkey. This region is the transition point to Europe and obtained data in this study could contribute to the control of heartworm disease in the area

Noise stress changes mRNA expressions of corticotropin-releasing hormone, its receptors in amygdala, and anxiety-related behaviors

Noise is a psychological, environmental stressor that activates limbic sites in the brain. Limbic sites such as the amygdala and the amygdaloid corticotropin-releasing hormone (CRH) system play an important role in integrating stress response. We investigated the association between noise exposures, CRH-related molecules in the amygdala, and behavioral alterations. In total 54 Sprague-Dawley rats were divided into the following three groups: Control (CON), acute noise exposure (ANE), and chronic noise exposure (CNE). The ANE group was exposed to 100 dB white noise only once in 4 h and the CNE group was exposed to the same for 4 h per day for 30 days. Expression profiles of CRH and its receptors CRH-R1 and CRH-R2 were analyzed by quantitative real-time polymerase chain reaction (qPCR). The same stress procedure was applied to the ANE and CNE groups for behavior testing. The anxiety responses of the animals after acute and chronic stress exposure were measured in the defensive withdrawal test. CNE upregulated CRH and CRH-R1 mRNA levels but downregulated CRH-R2 mRNA levels. ANE led to a decrease in both CRH-R1 and CRH-R2 expression. In the defensive withdrawal test, while the ANE increased, CNE reduced anxiety-like behaviors. The present study shows that the exposure of rats to white noise (100 dB) leads to behavioral alterations and molecule-specific changes in the CRH system. Behavioral alterations can be related to these molecular changes in the amygdala