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In JoVE (1)
Other Publications (6)
- Archives of Toxicology
- The International Journal of Neuroscience
- Transfusion and Apheresis Science : Official Journal of the World Apheresis Association : Official Journal of the European Society for Haemapheresis
- Clinical Hemorheology and Microcirculation
- PloS One
- Proceedings of the National Academy of Sciences of the United States of America
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Articles by Piray Atsak in JoVE
JoVE Neuroscience
מכרסמים כירורגיה Stereotaxic ועל צער בעלי חיים שיפורים תוצאה של ההתנהגות Neuroscience
1Department of Neuroscience, Section Anatomy, University Medical Center Groningen, University of Groningen, 2Animal Welfare Office, University of Groningen
ניתוח Stereotaxic על מכרסמים מאפשר ניהול ממוקד של תרופות או גירוי חשמלי והקלטות ב ער, התנהגות בעלי חיים. במצגת וידאו זה נדגים חידודים פרוצדורליים האחרונות להליך ארוכת זה כי שיעור ההישרדות משופרת בהצלחה ואובדן מופחת לאחר הניתוח המשקל.
Other articles by Piray Atsak on PubMed
The Effects of Low Dose Aluminum on Hemorheological and Hematological Parameters in Rats
Aluminum (Al) is a nonessential element and humans are constantly exposed to Al as a result of an increase in industrialization and improving technology practices. Al toxicity can induce several clinical disorders such as neurotoxicity, gastrointestinal toxicity, hepatotoxicity, bone diseases, and anemia. This study aimed at evaluating the possible effects of short term and low dose Al exposure on hemorheological and hematological parameters in rats. Fourteen young, male Wistar albino rats were divided into two groups: 1 mg/200 g body weight of aluminum sulfate (Al(2)(SO(4))(3) was injected intraperitoneally to the first group for two weeks, three times a week. The animals of the control group received only physiological saline solution during this period. At the end of the experimental period, anticoagulated blood samples were collected and hematological parameters were determined using an electronic hematology analyzer. Red blood cell (RBC) deformability and aggregation were measured using an ektacytometer (LORCA) and plasma and whole blood viscosities were determined with a Wells-Brookfield cone-plate rotational viscometer. Significant decreases in mean corpuscular volume (MCV), red blood cell (RBC) deformability at low shear stress levels, the aggregation half time (t1/2) and the amplitude (AMP) of aggregation and significant increments in whole blood viscosity (WBV) at native and 40% hematocrit (Hct) of Al-treated rats have been observed. In conclusion, low dose Al(2)(SO(4))(3) exposure for a short-time may be responsible for alterations in either rheological properties of blood or hemorheological properties through a remarkable effect on RBC membrane mechanical properties . These alterations may also play an important role in the development of anemia in the Al-treated animals.
Effect of Ingested Sulfite on Hippocampus Antioxidant Enzyme Activities in Sulfite Oxidase Competent and Deficient Rats
Animal tissues are exposed to sulfite used as a preservative in food and drugs, and generated from the catabolism of sulfur-containing amino acids. Sulfite, which is a very reactive and potentially toxic molecule, is detoxified by the enzyme sulfite oxidase (SOX). Laboratory animals can be made deficient in SOX by the administration of a high-tungsten/low molybdenum regimen. It has been suggested that SOX deficient rats might be used as a model for the prediction of sulfite toxicity in humans. The aim of this study was to investigate the effects of ingested sulfite on hippocampus superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) activities in SOX competent and deficient rats. Hippocampus SOD, CAT and GPx activities were found to be significantly increased by sulfite treatment in SOX competent groups. On the other hand, exposure to sulfite had no effect on antioxidant status in hippocampus of SOX deficient rats. In conclusion, these results suggest that hippocampus antioxidant capacity where defense mechanism against the oxidative challenge is up regulated by sulfite in SOX competent rats. This up regulation mechanism in antioxidant enzymes against to sulfite related oxidative stress is not observed in SOX deficient rats and remains to be explained.
Effect of Thrombocytapheresis on Blood Rheology in Healthy Donors: Role of Nitric Oxide
Platelet transfusions are increasingly being used to treat thrombocytopenic conditions. Because of anticoagulation, changes in blood composition and extracorporeal circulation, donor apheresis may cause alterations in hemorheology. This study aimed at investigating the effects of thrombocytapheresis on donor blood rheology. The effect of nitric oxide (NO) on donor red blood cell (RBC) deformability after thrombocytapheresis was also studied. Platelets were collected by a Haemonetics MCS 3p cell seperator. Blood samples were obtained before and 15 min after thrombocytapheresis. RBC deformability and aggregation were measured using an ektacytometer, whole blood viscosity (WBV) was determined with a cone-plate rotational viscometer. Donor RBCs were shown to be less deformable at all stress levels except 0.30 Pa after thrombocytapheresis and NO donor sodium nitroprusside (SNP, 10(-6) M) reversed the reduced deformability caused by thrombocytapheresis. It was observed that donor apheresis induces a decrement in RBC aggregation and WBV measured at standard hematocrit (Hct). No significant alterations were observed in WBV values determined at native Hct values. Thrombocytapheresis also resulted in a decrement in fibrinogen, total protein, cholesterol and albumin levels whereas Hct was found to be increased and serum glucose, triglyceride, hemoglobin levels unaltered after apheresis. These results suggest that, thrombocytapheresis causes alterations in hemorheological parameters and hence in the perfusion of the microvasculature of the donors and NO appears to have a protective effect on the impairment observed in RBC deformability.
Effects of Resistance Training Intensity on Deformability and Aggregation of Red Blood Cells
This study aimed to investigate the short and long-term effects of resistance exercise training (RET) performed at different intensities (moderate and submaximal) on red blood cell (RBC) deformability and aggregation. 14 young male subjects were divided into two groups: Moderate intensity group performed 3 sets of 12 repetitions at an intensity corresponding to 70% of one-repetition maximum (1RM) whereas submaximal intensity group performed 3 sets of 6 repetitions at 85% of 1RM for 6 weeks. Blood samples were obtained just before and immediately after the RET on the first and last day of the program. Hemorheological parameters were determined using an ektacytometer (LORCA), hematological parameters were evaluated by a hematology analyzer. RBC deformability was found to increase in both groups immediately after the RET but this elevation was significant only in the moderate intensity group on the first day. RBC aggregation significantly increased in both groups immediately after the RET on the first and last day of the program. It is concluded that RET performed at an intensity corresponding to 70% of 1RM alters RBC deformability more than training performed at 85% of 1RM. On the other hand, both training protocols affect RBC aggregation in a similar way.
Experience Modulates Vicarious Freezing in Rats: a Model for Empathy
The study of the neural basis of emotional empathy has received a surge of interest in recent years but mostly employing human neuroimaging. A simpler animal model would pave the way for systematic single cell recordings and invasive manipulations of the brain regions implicated in empathy. Recent evidence has been put forward for the existence of empathy in rodents. In this study, we describe a potential model of empathy in female rats, in which we studied interactions between two rats: a witness observes a demonstrator experiencing a series of footshocks. By comparing the reaction of witnesses with or without previous footshock experience, we examine the role of prior experience as a modulator of empathy. We show that witnesses having previously experienced footshocks, but not naïve ones, display vicarious freezing behavior upon witnessing a cage-mate experiencing footshocks. Strikingly, the demonstrator's behavior was in turn modulated by the behavior of the witness: demonstrators froze more following footshocks if their witness froze more. Previous experiments have shown that rats emit ultrasonic vocalizations (USVs) when receiving footshocks. Thus, the role of USV in triggering vicarious freezing in our paradigm is examined. We found that experienced witness-demonstrator pairs emitted more USVs than naïve witness-demonstrator pairs, but the number of USVs was correlated with freezing in demonstrators, not in witnesses. Furthermore, playing back the USVs, recorded from witness-demonstrator pairs during the empathy test, did not induce vicarious freezing behavior in experienced witnesses. Thus, our findings confirm that vicarious freezing can be triggered in rats, and moreover it can be modulated by prior experience. Additionally, our result suggests that vicarious freezing is not triggered by USVs per se and it influences back onto the behavior of the demonstrator that had elicited the vicarious freezing in witnesses, introducing a paradigm to study empathy as a social loop.
Glucocorticoids Interact with the Hippocampal Endocannabinoid System in Impairing Retrieval of Contextual Fear Memory
There is extensive evidence that glucocorticoid hormones impair the retrieval of memory of emotionally arousing experiences. Although it is known that glucocorticoid effects on memory retrieval impairment depend on rapid interactions with arousal-induced noradrenergic activity, the exact mechanism underlying this presumably nongenomically mediated glucocorticoid action remains to be elucidated. Here, we show that the hippocampal endocannabinoid system, a rapidly activated retrograde messenger system, is involved in mediating glucocorticoid effects on retrieval of contextual fear memory. Systemic administration of corticosterone (0.3-3 mg/kg) to male Sprague-Dawley rats 1 h before retention testing impaired the retrieval of contextual fear memory without impairing the retrieval of auditory fear memory or directly affecting the expression of freezing behavior. Importantly, a blockade of hippocampal CB1 receptors with AM251 prevented the impairing effect of corticosterone on retrieval of contextual fear memory, whereas the same impairing dose of corticosterone increased hippocampal levels of the endocannabinoid 2-arachidonoylglycerol. We also found that antagonism of hippocampal β-adrenoceptor activity with local infusions of propranolol blocked the memory retrieval impairment induced by the CB receptor agonist WIN55,212-2. Thus, these findings strongly suggest that the endocannabinoid system plays an intermediary role in regulating rapid glucocorticoid effects on noradrenergic activity in impairing memory retrieval of emotionally arousing experiences.
