scholarly journals Rapid Preconditioning Protects Rats against Ischemic Neuronal Damage after 3 but Not 7 Days of Reperfusion following Global Cerebral Ischemia

1997 ◽  
Vol 17 (2) ◽  
pp. 175-182 ◽  
Author(s):  
Miguel A. Pérez-Pinzón ◽  
Guang-Ping Xu ◽  
W. Dalton Dietrich ◽  
Myron Rosenthal ◽  
Thomas J. Sick
Keyword(s):  
Cerebral Ischemia ◽  
Neuronal Damage ◽  
Systemic Blood Pressure ◽  
Global Cerebral Ischemia ◽  
Extracellular Potassium ◽  
Artery Ligation ◽  
Clear Trend ◽  
Maximal Increase ◽  
Hippocampal Ca1 ◽  
Bilateral Carotid

Earlier studies indicated that sublethal ischemic insults separated by many hours may “precondition” and, thereby, protect tissues from subsequent insults. In Wistar rats, we examined the hypothesis that ischemic preconditioning (IPC) can improve histopathological outcome even if the “conditioning” and “test” ischemic insults are separated by only 30 min. Normothermic (36.5–37°C) global cerebral ischemia was produced by bilateral carotid artery ligation after lowering mean systemic blood pressure. The conditioning ischemic insult lasted 2 min and was associated with a time sufficient to provoke “anoxic depolarization” (AD) (i.e., the abrupt maximal increase in extracellular potassium ion activity). After 30 min of reperfusion, 10-min test ischemia was produced, and histopathology was assessed 3 and 7 days later. After 3 days of reperfusion, neuroprotection was most robust in the left lateral, middle and medial subsections of the hippocampal CA1 subfield and in the cortex, where protection was 91, 76, 70 and 86%, respectively. IPC also protected the right lateral, middle and medial subsections of the hippocampal CA1 region. These data demonstrate that neuroprotection against acute neuronal injury can be achieved by conditioning insults followed by only short (30 min) periods of reperfusion. However, neuroprotection almost disappeared when reperfusion was continued for 7 days. When test ischemia was decreased to 7 min, a clear trend of neuroprotection by IPC was observed. These data suggest that subsequent rescue of neuronal populations could be achieved with better understanding of the neuroprotective mechanisms involved in this rapid IPC model.

scholarly journals A Model of Global Cerebral Ischemia in C57 BL/6 Mice

2004 ◽  
Vol 24 (2) ◽  
pp. 151-158 ◽  
Author(s):  
Ichiro Yonekura ◽  
Nobutaka Kawahara ◽  
Hirofumi Nakatomi ◽  
Kazuhide Furuya ◽  
Takaaki Kirino
Keyword(s):  
Cerebral Ischemia ◽  
Genetic Background ◽  
Neuronal Degeneration ◽  
Neuronal Damage ◽  
Neuronal Injury ◽  
Genetically Engineered ◽  
Global Cerebral Ischemia ◽  
Vessel Occlusion ◽  
Bilateral Carotid ◽  
The Mean

A reproducible model of global cerebral ischemia in mice is essential for elucidating the molecular mechanism of ischemic neuronal injury. Such a model is particularly important in the mouse because many genetically engineered mutant animals are available. In C57BL/6 and SV129/EMS mice, we evaluated a three-vessel occlusion model. Occlusion of the basilar artery with a miniature clip was followed by bilateral carotid occlusion. The mean cortical cerebral blood flow was reduced to less than 10% of the preischemic value, and the mean anoxic depolarization was attained within 1 minute. In C57BL/6 mice, there was CA1 hippocampal neuronal degeneration 4 days after ischemia. Neuronal damage depended upon ischemic duration: the surviving neuronal count was 78.5 ± 8.5% after 8-minute ischemia and 8.4 ± 12.7% after 14-minute ischemia. In SV129/EMS mice, similar neuronal degeneration was not observed after 14-minute ischemia. The global ischemia model in C57BL/6 mice showed high reproducibility and consistent neuronal injury in the CA1 sector, indicating that comparison of ischemic outcome between wild-type and mutant mice could provide meaningful data using the C57BL/6 genetic background. Strain differences in this study highlight the need for consideration of genetic background when evaluating ischemia experiments in mice.

scholarly journals MK-801 (Dizocilpine) Protects the Brain from Repeated Normothermic Global Ischemic Insults in the Rat

1993 ◽  
Vol 13 (6) ◽  
pp. 925-932 ◽  
Author(s):  
Baowan Lin ◽  
W. Dalton Dietrich ◽  
Myron D. Ginsberg ◽  
Mordecai Y.-T. Globus ◽  
Raul Busto
Keyword(s):  
Cerebral Ischemia ◽  
Repeated Measures ◽  
Neuronal Damage ◽  
Brain Temperature ◽  
Global Cerebral Ischemia ◽  
Striatal Neurons ◽  
Ischemic Insult ◽  
Mk 801 ◽  
Bilateral Carotid ◽  
Ventrolateral Thalamus

We investigated the neuroprotective potential of MK-801 (dizocilpine), a noncompetitive N-methyl-d-aspartate (NMDA) antagonist, in the setting of three 5-min periods of global cerebral ischemia separated by 1-h intervals in halothane-anesthetized rats. Each ischemic insult was produced by bilateral carotid artery occlusions plus hypotension (50 mm Hg). Brain temperature was maintained at normothermic levels (36.5–37.0°C) throughout the experiment. MK-801 (3 mg/kg) (n = 6) or saline (n = 6) was injected intraperitoneally 45 min following the end of the first ischemic insult. Following 7-day survival, quantitative neuronal counts of perfusion-fixed brains revealed severe ischemic damage in hippocampal CA1 area, neocortex, ventrolateral thalamus, and striatum of untreated rats. By contrast, significant protection was observed in MK-801-treated rats. In area CA1 of the hippocampus, numbers of normal neurons were increased 11- to 14-fold by MK-801 treatment (p < 0.01). The ventrolateral thalamus of MK-801-treated rats showed almost complete histologic protection, and neocortical damage was reduced by 71% (p < 0.01). The degree of MK-801 protection of striatal neurons was less complete than that seen in other vulnerable structures, amounting to 63% for central striatum (p = 0.02, Mann–Whitney U test) and 48% in the dorsolateral striatum (NS). A repeated-measures analysis of variance demonstrated a highly significant overall protective effect of MK-801 treatment ( F1,10 = 37.2, p = 0.0001). These findings indicate that excitotoxic mechanisms play a major role in neuronal damage produced by repeated ischemic insults and that striking cerebroprotection is conferred by MK-801 administered following the first insult in animals with cerebral normothermia. NMDA antagonists may prove useful in patients at risk of repeated episodes of cerebral ischemia.

NCX3 knockout mice exhibit increased hippocampal CA1 and CA2 neuronal damage compared to wild-type mice following global cerebral ischemia

2008 ◽  
Vol 210 (1) ◽  
pp. 268-273 ◽  
Author(s):  
Graham J. Jeffs ◽  
Bruno P. Meloni ◽  
Sophie Sokolow ◽  
Andre Herchuelz ◽  
Stéphane Schurmans ◽  
...  
Keyword(s):  
Cerebral Ischemia ◽  
Knockout Mice ◽  
Neuronal Damage ◽  
Global Cerebral Ischemia ◽  
Wild Type ◽  
Hippocampal Ca1

scholarly journals Targeting Expression of hsp70i to Discrete Neuronal Populations Using the Lmo-1 Promoter: Assessment of the Neuroprotective Effects of hsp70i In vivo and In vitro

2001 ◽  
Vol 21 (8) ◽  
pp. 972-981 ◽  
Author(s):  
Stephen Kelly ◽  
Alison Bieneman ◽  
Karen Horsburgh ◽  
David Hughes ◽  
Michael V. Sofroniew ◽  
...  
Keyword(s):  
Cerebral Ischemia ◽  
Transgenic Mice ◽  
Caudate Nucleus ◽  
Neuronal Damage ◽  
Global Cerebral Ischemia ◽  
Specific Gene ◽  
Wild Type ◽  
Neuroprotective Effects ◽  
Bilateral Carotid

Transgenic technology provides a powerful means of studying gene regulation and specific gene function with complex mammalian systems. In this study, the authors exploited the specific and discrete neuronal expression pattern mediated by promoter 1 of the Lmo-1 gene to study the neuroprotective effects of the inducible form of heat shock protein 70kD (hsp70i) in primary hippocampal cultures in a mouse model of global cerebral ischemia. Targeting expression of hsp70i to hippocampal neurons protected these cells significantly from toxic levels of glutamate and oxidative stress (for example, exposure to 10 μmol/L free iron produced a 26% increase in lactate dehydrogenase release from neurons cultured from wild-type mice, but a 7% increase in neurons cultured from hsp70i transgenic mice). Bilateral carotid occlusion (25 minutes) produced significantly less neuronal damage in the caudate nucleus and posterior thalamus in hsp70i transgenic mice than in wild-type littermates (for example, 21% ± 9.3% and 12.5% ± 9.0% neuronal damage in lateral caudate nucleus of wild-type and hsp70i transgenic mice, respectively, P < 0.05). The current study highlights the utility of targeted expression of transgenes of interest in cerebral ischemia and demonstrates that expression of hsp70i alone is sufficient to mediate the protection of primary neurons from denaturing stress and that expression of human hsp70i in vivo plays crucial role in determining the fate of neurons after ischemic challenge.

scholarly journals Assessment of Postischemic Neurogenesis in Rats with Cerebral Ischemia and Propofol Anesthesia

2009 ◽  
Vol 110 (3) ◽  
pp. 529-537 ◽  
Author(s):  
Irina Lasarzik ◽  
Uta Winkelheide ◽  
Sonja Stallmann ◽  
Christian Orth ◽  
Astrid Schneider ◽  
...  
Keyword(s):  
Cerebral Ischemia ◽  
Spatial Learning ◽  
Neuronal Damage ◽  
Artery Occlusion ◽  
Carotid Artery Occlusion ◽  
High Dose ◽  
Sprague Dawley ◽  
Bilateral Carotid ◽  
Significant Difference ◽  
Treatment Naïve

Background Postischemic endogenous neurogenesis can be dose-dependently modulated by volatile anesthetics. The intravenous anesthetic propofol is used during operations with a risk of cerebral ischemia, such as neurosurgery, cardiac surgery, and vascular surgery. The effects of propofol on neurogenesis are unknown and, therefore, the object of this study. Methods Eighty male Sprague-Dawley rats were randomly assigned to treatment groups with propofol administration for 3 h: 36 mg x kg(-1) x h(-1) propofol with or without cerebral ischemia and 72 mg x kg(-1) x h(-1) propofol with or without cerebral ischemia. In addition, 7 rats with propofol administration for 6 h and 14 treatment-naive rats were investigated. Forebrain ischemia was induced by bilateral carotid artery occlusion and hemorrhagic hypotension. Animals received 5-bromo-2-deoxyuridine for 7 days. 5-Bromo-2-deoxyuridine-positive neurons were counted in the dentate gyrus after 9 and 28 days. Spatial learning in the Barnes maze and histopathologic damage of the hippocampus were analyzed. Results Propofol revealed no impact on basal neurogenesis. Cerebral ischemia increased the amount of new neurons. After 28 days, neurogenesis significantly increased in animals with low-dose propofol administered during cerebral ischemia compared with naive animals, whereas no significant difference was observed in animals with high-dose propofol during ischemia. Neuronal damage in the CA3 region was increased at 28 days with high-dose propofol. Postischemic deficits in spatial learning were not affected by propofol. Conclusions Independent effects of propofol are difficult to ascertain. Peri-ischemic propofol administration may exert secondary effects on neurogenesis by modulating the severity of histopathologic injury and thereby regenerative capacity of the hippocampus.

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