Cerebral Ischemia In Mongolian Gerbils Research Articles

Corrigendum: Radenovic L, Selakovic V, Andjus P.R. Neuroprotection by MK-801 following cerebral ischemia in Mongolian gerbils. Arch Biol Sci. 2008;60(3):341-346. DOI: 10.2298/ABS0803341R

The corresponding author has informed the Editor-in-Chief that Fig. 2 in the article: Neuroprotection by MK-801 following cerebral ischemia in Mongolian gerbils, published in the Archives of Biological Sciences in 2008, Vol. 60, Issue 3, is incorrect due to submission of wrong figure. <br><br><font color="red"><b> Link to the corrected article <u><a href="http://dx.doi.org/10.2298/ABS0803341R">10.2298/ABS0803341R</a></b></u>

Protective effect of olive leaf extract on hippocampal injury induced by transient global cerebral ischemia and reperfusion in Mongolian gerbils

The beneficial effects of antioxidant nutrients, as well as complex plant extracts, in cerebral ischemia/reperfusion brain injury are well known. Mediterranean diet, rich in olive products, is associated with lower incidence of cardiovascular disease, cancer, inflammation and stroke. In this study, the possible neuroprotective effect of standardized dry olive leaf extract (OLE) is investigated for the first time. Transient global cerebral ischemia in Mongolian gerbils was used to investigate the OLE effects on different parameters of oxidative stress and neuronal damage in hippocampus. The biochemical measurements took place at different time points (80 min, 2, 4 and 24 h) after reperfusion. The effects of applied OLE were compared with effects of quercetin, a known neuroprotective plant flavonoid. Pretreatment with OLE (100 mg/kg, per os) significantly inhibited production of superoxide and nitric oxide, decreased lipid peroxidation, and increased superoxide dismutase activity in all time points examined. Furthermore, OLE offered histological improvement as seen by decreasing neuronal damage in CA1 region of hippocampus. The effects of applied OLE were significantly higher than effects of quercetin (100 mg/kg, per os). Our results indicate that OLE exerts a potent neuroprotective activity against neuronal damage in hippocampus after transient global cerebral ischemia, which could be attributed to its antioxidative properties.

Comparative Ultrastructural Analysis of Mitochondria in the CA1 and CA3 Hippocampal Pyramidal Cells Following Global Ischemia in Mongolian Gerbils

Post-ischemic injury of the hippocampus unrolls at different levels and has both functional and structural implications. The deficiency in neuron energy metabolism is an initiating factor. We performed transmission electron microscopic (TEM) comparative analysis of mitochondria in excitatory spine synapses in CA1 stratum radiatum and CA3 hippocampal areas after 5 min of global cerebral ischemia in Mongolian gerbils, 4 and 7 days after reperfusion. Electron microscopy and unbiased morphometric methods were used to evaluate synaptic plasticity, and the number and size of mitochondria in synaptic terminals. We compared the morphological organization of mitochondria in presynaptic terminals between CA1 and CA3 areas in control and post-ischemic condition according to the following morphometric parameters: mitochondrial volume fraction, mitochondrial frequency in CA1 and CA3 terminals, mean number of mitochondria per presynaptic terminal, frequency of damaged mitochondria in terminals, and density of presynaptic terminals. Our ultrastructural study revealed statistically significant differences in morphometric parameters between CA1 and CA3 areas in control conditions, as well as in post-ischemic conditions. Also, we found temporal differences in measured parameters obtained 4 and 7 days after reperfusion. This study showed significant morphological differences in the organization of mitochondria in excitatory spine synapses between CA1 and CA3 areas, which corresponded with already known differences in functionality and sensitivity to the ischemic insult. Our conclusion is that revealed post-ischemic changes in mitochondrial distribution in presynaptic CA1 and CA3 terminals could be an indicator of hippocampal metabolic dysfunction and synaptic plasticity.

Neuroprotectionby MK-801 following cerebral ischemia in Mongolian gerbils

Global cerebral ischemia in Mongolian gerbils is an established model in experimental research on cerebral ischemia, which is characterized morphologically by selective neuronal damage in the hippocampus, striatum, and cortex. Elevated glutamate levels are thought to be a primary cause of neuronal death after global cerebral ischemia. The purpose of this study was to investigate the potential neuroprotective effects of dizocilpine malate (MK-801), a non-competitive glutamate antagonist, in the model of 10-min gerbil cerebral ischemia. Gerbils were given MK-801(3 mg/kg i.p.)or saline immediately after the occlusion. On day 4 after reperfusion, neuronal damage was examined in the hippocampus (30 ?m)and striatum slices (5 ?m)stained with hematoxylin/eosin, fluorescent Nissl staining and membrane tracer DiI. The striatum and C3 regions of the hippocampus were analyzed by confocal microscopy. Neuroprotection was determined by quantifying the degree of cell loss, reduction of morphologically damaged cells, and the degree of preservation of recog?nizable neuroanatomical pathways after the ischemic insult. Our results demonstrate that the neuronal damage induced by sustained ischemia is related to abnormalities in glutamatergic function associated with NMDA receptors. MK-801significantly prevented neuronal loss in the tested brain structures. All of this contributes to a better understanding of the given pathophysiological process causing ischemic neuronal damage. <br><br><font color="red"><b> This article has been corrected. Link to the correction <u><a href="http://dx.doi.org/10.2298/ABS160524054E">10.2298/ABS160524054E</a><u></b></font>

Neuroprotective effect of MnTMPyP, a superoxide dismutase/catalase mimetic in global cerebral ischemia is mediated through reduction of oxidative stress and DNA fragmentation

Excessive generation of free radicals and decreased levels of the antioxidant enzymes such as superoxide dismutase (SOD) and catalase have been observed after brain ischemic reperfusion injury. In the present study, we have investigated the neuroprotective potential of MnTMPyP (Mn(III)tetrakis(1-methyl-4-pyridyl)porphyrin pentachloride), a SOD/Catalase mimetic in bilateral carotid artery occlusion model of global cerebral ischemia in Mongolian gerbils. Five minutes of bilateral carotid artery occlusion produced global cerebral ischemia, which was evident from the neurological deficits, spontaneous motor activity and the decrease in the number of viable hippocampal CA1 neurons. Global ischemia was also associated with increased levels of malondialdehyde, decreased levels of SOD and catalase, and increased TUNEL (terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling) positive cells, indicating oxidative stress and DNA fragmentation. Administration of a single dose of MnTMPyP, 1 mg/kg i.p. (30 min before occlusion), produced no significant neuroprotection; however, 3 mg/kg i.p. (30 min before to occlusion) produced significant reduction in neurological score, spontaneous motor activity and CA1 pyramidal neuronal damage. MnTMPyP also attenuated the increased levels of malondialdehyde and improved the levels of SOD and catalase, and inhibited DNA fragmentation in the ischemic animals. Multiple administration of MnTMPyP, 3 mg/kg i.p. (three times: 30 min before, 1 h and 3 h after occlusion), produced better neuroprotection as compared to single dose administration. This study demonstrates that the neuroprotective effect of MnTMPyP in global ischemia is mediated through reduction in oxidative stress and DNA fragmentation.

Neuroprotective Effects of Trolox in Global Cerebral Ischemia in Gerbils

Stroke is a third leading cause of death and oxygen free radicals have been shown to be involved in its pathophysiology. In the present study, we have investigated neuroprotective potential of trolox, a free radical scavenger in bilateral carotid arteries occlusion (5 min) model of global cerebral ischemia in Mongolian gerbils. Gerbils were treated with trolox (3, 10 or 30 mg/kg, i.p.) 30 min prior to occlusion. There was a significant increase in neurological symptoms and locomotor activity in ischemic animals as compared with the sham-operated animals. These effects were attenuated by trolox 30 mg/kg, i.p. Significant increase in the number of the surviving neurons in the hippocampal CA1 pyramidal region was observed in ischemic animals treated with trolox 30 mg/kg, i.p. There was significant increase in the level of malondialdehyde (MDA) in ischemic animals indicating oxidative stress. Elevated levels of MDA in ischemic animals (25.79+/-3.34 microM/mg of protein) were reduced (16.43+/-3.32 microM/mg of protein) and (8.98+/-0.89 microM/mg of protein) by trolox 10 and 30 mg/kg, i.p., respectively. This study demonstrates the neuroprotective potential of trolox in global cerebral ischemia in gerbils.

Effect of D-003, a Mixture of Very-Long-Chain Aliphatic Acids Purified from Sugarcane Wax, on Cerebral Ischemia in Mongolian Gerbils

D-003 is a mixture of very-high-molecular-weight aliphatic acids purified from sugar cane wax (Saccharum officinarum), which inhibits platelet aggregation and lipid peroxidation. The objective of the present study was to evaluate the effect of D-003 on cerebral ischemia induced by ischemia-reperfusion (I-R) in Mongolian gerbils. Two experimental series were conducted. The first series investigated the effects of D-003 on cerebral edema, neurological symptoms, and mortality in Mongolian gerbils with cerebral ischemia induced by I-R, while the second series investigated the effects on histological markers of cerebral injury, such as edema intensity (vacuolization) and cerebral necrosis. Animals were randomly distributed in five experimental groups: a sham-operated group experiencing surgical handling except the clamping and orally treated with Tween/water vehicle and four groups subjected to the I-R surgical procedure. One of these groups was treated with the same vehicle, and the other three groups received D-003 at 25, 100, and 200 mg/kg, respectively. All treatments were administered for 14 days. D-003 (200 mg/kg) significantly reduced the cerebral edema and clinical symptoms provoked by I-R compared with the positive control group, whereas lower doses (25 and 100 mg/kg) were not effective. Positive control animals showed an injury profile characterized by swelling (tissue vacuolization) and necrosis of neurons in all areas of the brain studied (frontal cortex, hippocampus, and striatum). The results of the histological study were consistent with those observed by determining cerebral edema and symptoms observation. Thus, D-003 at 200 mg/kg significantly reduced histological markers of brain injury (swelling and necrosis) compared with the control group. It is concluded that D-003 administered orally at 200 mg/kg for 14 days protected against cerebral damage caused by bilateral cerebral ischemia in Mongolian gerbils.

Capsaicin exhibits neuroprotective effects in a model of transient global cerebral ischemia in Mongolian gerbils

1. Capsaicin, the irritant principle of hot peppers, is a vanilloid agonist known to activate the transient receptor potential channel vanilloid subfamily member 1 (VR1), recently reported to be involved in neurodegeneration. The present study investigated the role of VR1 in a model of global cerebral ischemia in gerbils. 2. Over the dose range tested, capsaicin (0.01, 0.025, 0.05, 0.2 and 0.6 mg kg(-1)), given 5 min after recirculation, dose-dependently antagonized the ischemia-induced electroencephalographic total spectral power decrease and restored relative frequency band distribution evaluated 7 days after ischemia. 3. Capsaicin, at all tested doses, fully prevented ischemia-induced hyperlocomotion evaluated 1 day after ischemia. 4. Capsaicin dose-dependently antagonized ischemia-induced memory impairment evaluated in a passive avoidance task, 3 days after ischemia. 5. Capsaicin showed a dose-dependent hypothermic effect evaluated for 2 h after recirculation. 6. At 7 days after ischemia, a progressive survival of pyramidal cells in the CA1 subfield in capsaicin-treated gerbils, with a maximum of 80%, at a dose of 0.2 mg kg(-1), was obtained. 7. The selective VR1 antagonist, capsazepine (0.01 mg kg(-1)), reversed capsaicin-induced protective effects, in a competitive manner. 8. These results suggest that the neuroprotective effect of capsaicin may be attributable, at least in part, to VR1 desensitization and provide a valuable target for development of interventional pharmacological strategies.

Changes in expression of mRNAs in the gerbil hippocampus following transient forebrain ischemia

The phenomenon of delayed neuronal death in CA 1 neurons following brief duration of global ischemia has eluded definitive explanation. Using a differential display technique, we examined changes in expression ofmRNAs in the hippocampus following 5-min cerebral ischemia in Mongolian gerbils.. Under pentobarbital anesthesia, gerbils were sacrificed by decapitation at 6 h (n = 20) and 2 days (n = 20) after ischemia, and sham-operated gerbils (n = 20) were sacrificed at 6 h after surgery. Total RNA was isolated from the hippocampal samples in each group for the differential display analysis. The mRNAs were classified into three patterns; gradual disappearance, decrease and recovery, and new appearance. Representative mRNAs in three patterns were subcloned and sequenced partly. An mRNA in the gradual disappearance pattern showed homologous with neuronal pentraxin. In situ hybridization and Northern blot analyses of neuronal pentraxin revealed the gradual disappearance pattern. An mRNA in the decrease and recovery pattern showed homologous with 14-3-3 protein y-subtype, and an mRNA in the new e appearance pattern showed no homology in the data base. The differential display analysis is a usefultechnique with which to investigate changes in expression ofmRNAs following transient cerebral ischemia. The novel mRNA may be involved in the treatment of cerebral ischemia. Further studies are necessary for this point. [Neural Res 2000; 22: 825-831]

Delayed neuronal death suggestive of apoptosis following transient global cerebral ischemia in Mongolian gerbils

Delayed neuronal death suggestive of apoptosis following transient global cerebral ischemia in Mongolian gerbils

Adenosine A1 and A3 selectiveN-alkoxypurines as novel cytokine modulators and neuroprotectants

The synthesis, purinergic receptor binding, and biological activity of a series of novel N-alkoxyadenosine A 3 ligands is described. Several reference adenosine A 3 receptor agonists, e.g., N-(3-iodobenzyl)adenosine-5'-methyluronamide (IB-MECA) contain a 4'-ribosylalkylamide moiety as well as a large 6-amino substituent. We found that this 4'-amide could be replaced with a range of other furanosyl-4'-functional groups including vinyl, chloromethyl, acetoxymethyl, methoxymethyl, and isoxazolyl; the target molecules exhibited potent and selective binding to the recombinant human A 3 receptor. Furthermore, the bulky phenylmethyl 6-amino substituent in IB-MECA has been replaced by methoxy, also with retention of A 3 receptor affinity. The new N-alkoxyadenosine derivatives were examined for their ability to inhibit the production of the cytokine tumor necrosis factor alpha (TNF-α), which is indicative of A 3 agonist effect, and some examples exhibited a protective effect in both a rodent seizure model and global cerebral ischemia in Mongolian gerbils.

Beneficial effects of TDN-345, a novel Ca 2+ antagonist, on ischemic brain injury and cerebral glucose metabolism in experimental animal models with cerebrovascular lesions

The effects of TDN-345 on mortality and ischemic neurological deficit following transient global cerebral ischemia in Mongolian gerbils and also the rate of local cerebral glucose utilization (LCGU) in stroke-prone spontaneously hypertensive rats (SHRSP) with cerebrovascular lesions were investigated. In Mongolian gerbils, ischemia was produced by clamping the bilateral common carotid arteries for 15 min. TDN-345 (0.1–1.0 mg/kg) dose-dependently decreased the mortality and ischemic neurological deficit score when administered orally twice, 60 min before ischemia and 90 min after recirculation. Additionally, TDN-345 (0.2 or 1.0 mg/kg, p.o. once daily for 3 weeks after the onset of stroke) decreased the mortality and recurrence of stroke in SHRSP. To determine the site of action of TDN-345 in the brain, the rate of LCGU in various brain regions in SHRSP with stroke was examined using a [ 14C]2-deoxy- d-glucose method. The rate of LCGU decreased significantly in all the brain regions in SHRSP with stroke compared with Wistar–Kyoto (WKY) control rats, whereas the reduction in the rate of LCGU in SHRSP with stroke was prevented by TDN-345 treatment, especially in the sensorimotor cortex and locus coeruleus. These results suggest that TDN-345 has therapeutic efficacy in the treatment of cerebrovascular disease.

Changes in locomotor activity and passive avoidance task performance induced by cerebral ischemia in Mongolian gerbils.

We investigated changes in locomotor activity, passive avoidance task performance, and hippocampal CA1 neurons induced by cerebral ischemia in Mongolian gerbils to examine the relation between these behavioral changes and CA1 neuronal damage. Spontaneous locomotor activity was measured using the open field method before and 1, 3, 7, 14, or 28 days after 1- to 5-minute occlusion of the bilateral common carotid arteries. Locomotor activity after the second episode of 5-minute ischemia was also measured at 1-month intervals. The passive avoidance task was performed 7 or 28 days after induced ischemia. Histopathological changes in CA1 neurons after ischemia were assessed. Locomotor activity was increased 1 and 3 days after induced ischemia but not 14 and 28 days later. When the gerbils were again subjected to 5-minute ischemia 1 month after the initial 5-minute induced ischemia, locomotor activity even 1 day later was significantly increased. In contrast, passive avoidance impairment depended on the duration of ischemia, as determined 7 and 28 days after induced ischemia. Hippocampal CA1 neuronal damage was progressive, that is, changes in CA1 neurons were apparent even 1 day after 5 minutes of induced ischemia, and the CA1 neurons disappeared 7 days after 5 minutes of ischemia. Passive avoidance impairment after ischemia is related to damage of CA1 neurons. Changes in locomotor activity after induced ischemia do not seem to be linked to CA1 neuronal damage.

Changes of [3H]cyclic adenosine monophosphate binding in the gerbil brain following transient cerebral ischemia: an autoradiographic study and investigation of the effects of vinconate and pentobarbital.

We studied the alterations in binding of cyclic AMP as an indicator of particulate cyclic AMP-dependent protein kinase binding activity following transient cerebral ischemia in Mongolian gerbils and examined the effects of vinconate and pentobarbital against alterations in the binding. Animals were allowed to survive for 5 h and 7 days after 10 min of cerebral ischemia induced by bilateral occlusion of common carotid arteries. [3H]Cyclic AMP binding was significantly reduced in the hippocampus 5 h after ischemia, whereas the striatum showed no significant change in the binding. Seven days after ischemia, a severe reduction of [3H]cyclic AMP binding was noted in the dorsolateral striatum, hippocampal CA1 and CA3 sectors, and dentate gyrus. Intraperitoneal administration of vinconate (100 or 300 mg/kg) showed a significant elevation of [3H]cyclic AMP binding in the striatum, stratum pyramidale of hippocampal CA1 and CA3 sectors, and dentate gyrus 5 h after ischemia. By contrast, the intraperitoneal administration of pentobarbital (40 mg/kg) showed no significant alteration of [3H]cyclic AMP binding in most of these regions. However, vinconate and pentobarbital prevented a significant reduction of [3H]cyclic AMP binding in the dorsolateral striatum and stratum pyramidale of hippocampal CA3 sector 7 days after ischemia, although both drugs failed to prevent damage to the hippocampal CA1 sector. These results suggest that alteration in cyclic AMP binding may not be a major factor in causing ischemic neuronal damage.

Postischemic alteration of muscarinic acetylcholine and adenosine A1 binding sites in gerbil brain

We studied the alterations in the binding of muscarinic cholinergic and adenosine A1 receptors following transient cerebral ischemia in Mongolian gerbils and examined the effects of the novel vinca alkaloid derivative vinconate and pentobarbital against the alterations in the binding of these receptors. Animals were allowed to survive for 5 h and 7 days after 10 min of cerebral ischemia induced by bilateral occlusion of common carotid arteries. [3H]Quinuclidinyl benzilate (QNB) and [3H]cyclohexyladenosine (CHA) were used to label muscarinic cholinergic and adenosine A1 receptors, respectively. The [3H]QNB and [3H]CHA bindings showed no significant alteration in the gerbil brain 5 h after ischemia. However, these bindings in the striatum, the hippocampal CA1 sector, and the hippocampal CA3 sector revealed a significant reduction 7 days after ischemia. The [3H]CHA binding also showed a significant decline in the dentate molecular layer 7 days after ischemia. Intraperitoneal application of vinconate (100 and 300 mg/kg) 10 min and pentobarbital (40 mg/kg) 30 min before ischemia showed a mild reduction in the [3H]CHA binding in the brain 5 h after ischemia. Especially, the reduction was found in the hippocampal CA1 sector and the dentate molecular layer. However, the [3H]QNB binding revealed no significant alteration in the brain 5 h after ischemia. Seven days after ischemia, both drugs prevented a marked reduction in the [3H]CHA binding in the striatum, but not in the hippocampal CA1 sector, the hippocampal CA3 sector, and the dentate molecular layer. By contrast, vinconate and pentobarbital failed to prevent the reduction in the [3H]QNB binding in the striatum. Morphological study indicated that vinconate and pentobarbital ameliorated the neuronal damage to the striatum, but not the hippocampal damage 7 days after ischemia. This histological finding was relatively consistent with the alteration in the [3H]CHA binding. These receptor autoradiographic and histological data suggest that vinconate and pentobarbital can protect the brain from both cellular and functional consequences of ischemia. These findings are of interest in relation to the mechanisms of ischemic brain damage.

Effects of ketanserin and mianserin on delayed neuronal death induced by cerebral ischemia in Mongolian gerbils.

We examined whether ketanserin and mianserin, drugs with 5-HT2 receptor antagonistic effects, would have protective effects in Mongolian gerbils on delayed neuronal death induced by cerebral ischemia. When training and test sessions in the passive avoidance task were carried out 6 and 7 days after 3 min of ischemia, passive avoidance impairment was apparent. Destruction and disappearance was apparent in the hippocampal CA1 neurons at 7 days after the induced ischemia. Administration of ketanserin (5-20 mg/kg) and mianserin (5-20 mg/kg) led to better passive avoidance and prevented the delayed neuronal death induced by the ischemia. These effects of ketanserin and mianserin were not inhibited by treatment with the cholinergic blocker scopolamine (5 mg/kg). Thus, ketanserin and mianserin have a protective effect on delayed neuronal death in gerbils and the effects of these drugs are not mediated by serotonergic and cholinergic systems.

Cholinomimetic activity of minaprine is related to the amelioration of delayed neuronal death in gerbils

We attempted to determine if the cholinomimetic activity of the psychotropic drug minaprine was related to the amelioration of the delayed neuronal death induced by cerebral ischemia in Mongolian gerbils. Minaprine improved the passive avoidance deficit induced by cerebral ischemia, and the histopathological ischemic neuronal changes in the hippocampal CA1 neurons were diminished. These effects were completely inhibited by treatment with the cholinergic blocker scopolamine. Rectal temperature fell about 1.5°C immediately after cerebral ischemia and hyperthermia occurred 30 and 60 min after recirculation. Minaprine had no effect on body temperature before or after ischemia. Physostigmine and tetrahydroaminoacridine (THA), drugs which stimulate the cholinergic system, improved passive avoidance deficits and prevented the delayed neuronal death. These effects of physostigmine and THA were completely inhibited by scopolamine. Pentobarbital and diazepam also improved the passive avoidance deficit and prevented the destruction of CA1 neurons. In contrast with minaprine, these effects of pentobarbital and diazepam were not inhibited by scopolamine. As the protective effect of minaprine against ischemia-induced delayed neuronal death is related to cholinomimetic activities, these events differ from those seen with pentobarbital and diazepam.

P-019 - Changes in locomotor activities induced by cerebral ischemia in Mongolian gerbils

P-019 - Changes in locomotor activities induced by cerebral ischemia in Mongolian gerbils

P-023 - A possible involvement of CCK-A receptor in ceru1etide-induced protection against neuronal cell death following cerebral ischemia in mongolian gerbils

P-023 - A possible involvement of CCK-A receptor in ceru1etide-induced protection against neuronal cell death following cerebral ischemia in mongolian gerbils

Epileptic activity following cerebral ischemia in mongolian gerbils is depressed by CPP, a competitive antagonist of the [formula omitted] receptor

A 10-min bilateral carotid occlusion (BCO) in Mongolian gerbils induces transient generalized epileptic discharges in the hippocampal and cortical regions, which are followed by long lasting interictal spiking activity. An initial peak of this activity occurs within 18–36 h after BCO, then it decreases slowly and completely disappears by the 6th–7th day. On the 7th day, morphological evidence shows a selective loss of CA1 hippocampal neurons. 4-(3-Phosphonopropyl)-2-piperazine-carboxylic acid (CPP), a competitive antagonist of the N- methyl- d-aspartate (NMDA) receptor was administered (7 or 15 mg/kg i.p.) immediately after clamping, and again every 12 h for 3 consecutive days. It induced a dose-related depression of epileptic activity, while, on the other hand, at both dosages, it always prevented the loss of CA1 neurons. The results are discussed in view of the different mechanisms mediating cell damage and epileptic activity.