The present study reports on the acute effects of MK-801 on the histopathological outcome and blood flow changes during focal cerebral ischemia and reperfusion. In addition, acute changes in the EEG and blood pressure are also reported. In 16 halothane-anesthetized cats, the left middle cerebral artery (MCA) was occluded for 2 h followed by 4 h of reperfusion. Thirty minutes after the onset of ...

Several studies have demonstrated that systemically administered N-methyl-d-aspartate (NMDA) receptor antagonists increase serotonin (5-HT) and glutamate release in the medial prefrontal cortex (mPFC). Previously we showed that the perfusion of clozapine in the mPFC prevented the MK-801-induced increase in extracellular glutamate and 5-HT whereas haloperidol blocked only the effect of MK-801 on...

The experiment explored the influence of glutamic acid (Glu) and the NMDA-receptor antagonist dizocilpine maleate (MK-801) on the pain-evoked responses of pain-excitation neurons (PEN) in the nucleus accumbens (NAc) of rats. The trains of electric impulses applied to the sciatic nerve were used as noxious stimulation. The discharges of PEN in NAc were recorded by glass microelectrode. We observ...

Huntington's Disease (HD) is a common neurodegenerative disorder characterized by motor disturbances, subcortical dementia and psychiatric disturbances. Pathogenesis of HD revolves so far around excitatory amino acids as the primary cause of neuronal loss. However, number of recent reports suggests the involvement of excitotoxicity and oxidative damage. In the present study, first the dose of q...

The effects of the noncompetitive N-methyl-D-aspartate antagonist MK-801 on infarct size and systemic variables after middle cerebral artery occlusion in spontaneously hypertensive and Fischer-344 rats were investigated. Two doses (0.5 and 5 mg/kg) administered before the induction of ischemia were studied. MK-801 significantly reduced the neocortical volume of infarction (by about 32% at both ...

Large unilateral visual cortex lesions produce enduring contralesional visual orientation deficits. To examine whether glutamate excitotoxicity is involved in establishing these deficits, cats were pretreated with the NMDA receptor antagonist dizocilpine (MK-801) 30 min before unilateral visual cortex ablation. Pretreated MK-801 animals were trained first in an orientation task in which they we...

The contribution of glutamatergic and dopaminergic mechanisms to bladder hyperactivity after left middle cerebral artery occlusion was evaluated by determining the effects of intravenous cumulative doses of an N-methyl-d-aspartate (NMDA) glutamatergic antagonist (MK-801) and D1-selective (Sch-23390), D2-selective (sulpiride), or nonselective (haloperidol) dopaminergic antagonists on bladder act...

AIM To investigate whether or not histamine is involved in spatial memory deficits induced by dizocilpine (MK-801) as evaluated by 8-arm radial maze of rats. METHODS 8-Arm (4-arm baited) radial maze was used to measure spatial memory in rats. RESULTS Bilaterally intrahippocampal (ih) injection of MK-801 (0.3 microg/site) impaired working memory and reference memory in rats. Both histamine (...

N-methyl-D-aspartate receptor/channel (NMDAR) and voltage-dependent calcium channel (VDCC) antagonists applied independently reduce the magnitude of long-term potentiation (LTP) in area CA1 of the hippocampal slice preparation. When used in combination, the antagonists completely block the induction of LTP. In urethan-anesthetized rats we examined the effect of the NMDAR blocker MK-801 (0.1 mg/...

In a synapse, spontaneous and action-potential-driven neurotransmitter release is assumed to activate the same set of postsynaptic receptors. Here, we tested this assumption using (+)-5-methyl-10,11-dihydro-5H-dibenzo [a,d] cyclohepten-5,10-imine maleate (MK-801), a well characterized use-dependent blocker of NMDA receptors. NMDA-receptor-mediated spontaneous miniature EPSCs (NMDA-mEPSCs) were ...