scholarly journals Olanzapine Reverses MK-801-Induced Cognitive Deficits and Region-Specific Alterations of NMDA Receptor Subunits

2018 ◽  
Vol 11 ◽  
Author(s):  
Xiao Liu ◽  
Jitao Li ◽  
Chunmei Guo ◽  
Hongli Wang ◽  
Yaxin Sun ◽  
...  
Keyword(s):  
Nmda Receptor ◽  
Cognitive Deficits ◽  
Mk 801 ◽  
Nmda Receptor Subunits

scholarly journals Effect of dizocilpine (MK-801) on the working memory of rats on a three-panel runway apparatus

2018 ◽  
Vol 7 (12) ◽  
pp. 2373
Author(s):  
Naveen Kumar ◽  
Navin Budania ◽  
Arka Mondal ◽  
Sana Tafseer ◽  
Siddarth Ahuja ◽  
...  
Keyword(s):  
Working Memory ◽  
Animal Model ◽  
Nmda Receptor ◽  
Animal Models ◽  
Receptor Antagonist ◽  
Cognitive Deficits ◽  
Latency Period ◽  
Nmda Receptor Antagonist ◽  
Memory Errors ◽  
Mk 801

Background: Understanding the processes underlying cognitive functions is a prerequisite to develop strategies for the treatment of cognitive deficits. There is a great need for valid animal models for investigating the cognitive enhancing effects of potential therapeutics. Many studies have investigated animal models of cognitive deficits by using animals treated with compounds that compromise cognitive abilities. Glutamate, an excitatory neurotransmitter and abundantly distributed in the central nervous system is involved in memory processes through N-methyl-d-aspartate (NMDA) receptors. The behavioural consequences of blocking the NMDA receptor provide the rationale for cognitive impairment as an animal model for the cognitive deficits associated with dementia. Authors investigated the effect of dizocilpine (MK-801), an NMDA-receptor antagonist (non-competitive) on the working memory in rats using the three-panel runway apparatus.Methods: Total 24 trained male albino rats were randomly divided into 4 groups of 6 animals each. Varying doses of MK-801 were administered to the animals. Working memory errors and latency periods were evaluated on the three panel Runway apparatus.Results: Treatment with MK-801 at the dose of 0.03mg/ kg did not result in any significant change in working memory errors or latency period in comparison to saline control. MK-801 treatment at dose of 0.1mg/kg and 0.3mg/kg resulted in a significant increase in the number of working memory errors and latency period as compared to control.Conclusions: Authors conclude that MK-801 treatment in the dose of 0.1mg/ kg and 0.3mg/kg resulted in working memory deficits on the three-panel runway apparatus. Rats with cognitive deficits induced by the prototypical N-methyl-d-aspartate (NMDA) receptor antagonist MK-801 may provide a relevant animal model of dementia based on the mechanistic approach of blocking NMDA/glutamatergic signalling.

scholarly journals In vivo glucose metabolism and glutamate levels in mGluR5 knockout mice: a multimodal neuroimaging study using [18F]FDG microPET and MRS

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Yo-Han Joo ◽  
Yun-Kwan Kim ◽  
In-Gyu Choi ◽  
Hyeon-Jin Kim ◽  
Young-Don Son ◽  
...  
Keyword(s):  
Nmda Receptor ◽  
Glucose Metabolism ◽  
Cerebral Glucose Metabolism ◽  
Functional Coupling ◽  
Resonance Spectroscopy ◽  
Acute Administration ◽  
Multimodal Neuroimaging ◽  
Mk 801 ◽  
Genetic Ablation ◽  
Neuroimaging Study

Abstract Background Perturbed functional coupling between the metabotropic glutamate receptor-5 (mGluR5) and N-methyl-d-aspartate (NMDA) receptor-mediated excitatory glutamatergic neurotransmission may contribute to the pathophysiology of psychiatric disorders such as schizophrenia. We aimed to establish the functional interaction between mGluR5 and NMDA receptors in brain of mice with genetic ablation of the mGluR5. Methods We first measured the brain glutamate levels with magnetic resonance spectroscopy (MRS) in mGluR5 knockout (KO) and wild-type (WT) mice. Then, we assessed brain glucose metabolism with [18F]fluorodeoxyglucose ([18F]FDG) positron emission tomography before and after the acute administration of an NMDA antagonist, MK-801 (0.5 mg/kg), in the same mGluR5 KO and WT mice. Results Between-group comparisons showed no significant differences in [18F]FDG standardized uptake values (SUVs) in brain of mGluR5 KO and WT mice at baseline, but widespread reductions in mGluR5 KO mice compared to WT mice after MK-801 administration (p < 0.05). The baseline glutamate levels did not differ significantly between the two groups. However, there were significant negative correlations between baseline prefrontal glutamate levels and regional [18F]FDG SUVs in mGluR5 KO mice (p < 0.05), but no such correlations in WT mice. Fisher’s Z-transformation analysis revealed significant between-group differences in these correlations (p < 0.05). Conclusions This is the first multimodal neuroimaging study in mGluR5 KO mice and the first report on the association between cerebral glucose metabolism and glutamate levels in living rodents. The results indicate that mGluR5 KO mice respond to NMDA antagonism with reduced cerebral glucose metabolism, suggesting that mGluR5 transmission normally moderates the net effects of NMDA receptor antagonism on neuronal activity. The negative correlation between glutamate levels and glucose metabolism in mGluR5 KO mice at baseline may suggest an unmasking of an inhibitory component of the glutamatergic regulation of neuronal energy metabolism.

scholarly journals Ketamine Produces a Long-Lasting Enhancement of CA1 Neuron Excitability

2021 ◽  
Vol 22 (15) ◽  
pp. 8091
Author(s):  
Grace Jang ◽  
M. Bruce MacIver
Keyword(s):  
Nmda Receptor ◽  
Potassium Channel ◽  
Receptor Antagonist ◽  
Hippocampal Slices ◽  
Nmda Receptor Antagonist ◽  
Channel Block ◽  
Mk 801 ◽  
Ca1 Region ◽  
Excitatory Transmission ◽  
Ketamine Anesthesia

Ketamine is a clinical anesthetic and antidepressant. Although ketamine is a known NMDA receptor antagonist, the mechanisms contributing to antidepression are unclear. This present study examined the loci and duration of ketamine’s actions, and the involvement of NMDA receptors. Local field potentials were recorded from the CA1 region of mouse hippocampal slices. Ketamine was tested at antidepressant and anesthetic concentrations. Effects of NMDA receptor antagonists APV and MK-801, GABA receptor antagonist bicuculline, and a potassium channel blocker TEA were also studied. Ketamine decreased population spike amplitudes during application, but a long-lasting increase in amplitudes was seen during washout. Bicuculline reversed the acute effects of ketamine, but the washout increase was not altered. This long-term increase was statistically significant, sustained for >2 h, and involved postsynaptic mechanisms. A similar effect was produced by MK-801, but was only partially evident with APV, demonstrating the importance of the NMDA receptor ion channel block. TEA also produced a lasting excitability increase, indicating a possible involvement of potassium channel block. This is this first report of a long-lasting increase in excitability following ketamine exposure. These results support a growing literature that increased GABA inhibition contributes to ketamine anesthesia, while increased excitatory transmission contributes to its antidepressant effects.

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