Influence of different anaesthetics on extracellular aminoacids in rat brain

Rozza, A.; Masoero, Elisabetta; Favalli, L.; Lanza, Enrica; Govoni, Stefano; Rizzo, Vittoria; Montalbetti, Lorenza

doi:10.1016/s0165-0270(00)00266-1

Cited by 35 publications

(23 citation statements)

References 20 publications

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“…The result is in accord with reported studies of the effect of pentobarbital on GLU uptake in cultured astrocytes (reviewed by Sonnewald et al 2002). As for the effect on extracellular GLU concentration, pentobarbital anesthesia (50 mg/kg weight intraperitoneally) was shown to cause no change in basal GLU ECF concentration in rat brain measured by in vivo microdialysis (Rozza et al 2000) and this was confirmed in our laboratory. Pentobarbital acts as an anesthetic primarily by binding to an allosteric site on the GABA A receptor, thereby increasing Cl -conductance and hyperpolarization of the postsynaptic membrane that enhance GABAergic neural inhibition (reviewed by Ito et al 1996).…”

Section: Contribution Of Neurotransmitter Glu Ecf To Gln Synthesissupporting

confidence: 91%

Glial uptake of neurotransmitter glutamate from the extracellular fluid studiedin vivoby microdialysis and¹³C NMR

Kanamori

Ross

Kondrat

2002

Journal of Neurochemistry

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Glial uptake of neurotransmitter glutamate (GLU) from the extracellular fluid was studied in vivo in rat brain by 13 C NMR and microdialysis combined with gas-chromatography/massspectrometry. Brain GLU C5 was 13 C enriched by intravenous [2,5-13 C]glucose infusion, followed by [ 12 C]glucose infusion to chase 13 C from the small glial GLU pool. This leaves [5-13 C]GLU mainly in the large neuronal metabolic pool and the vesicular neurotransmitter pool. During the chase, the 13 C enrichment of whole-brain GLU C5 was significantly lower than that of extracellular GLU (GLU ECF ) derived from exocytosis of vesicular GLU. Glial uptake of neurotransmitter N enrichment of precursor NH 3 (0.87 ± 0.014), the rate of synthesis of GLN (V¢ GLN ), derived from neurotransmitter GLU ECF , was determined to be 6.4 ± 0.44 lmol/g/h. Comparison with V GLN measured previously by an independent method showed that the neurotransmitter provides 80-90% of the substrate GLU pool for GLN synthesis. Hence, under our experimental conditions, the rate of 6.4 ± 0.44 lmol/g/h also represents a reasonable estimate for the rate of glial uptake of GLU ECF , a process that is crucial for protecting the brain from GLU excitotoxicity.

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Section: Contribution Of Neurotransmitter Glu Ecf To Gln Synthesissupporting

confidence: 91%

Glial uptake of neurotransmitter glutamate from the extracellular fluid studiedin vivoby microdialysis and¹³C NMR

Kanamori

Ross

Kondrat

2002

Journal of Neurochemistry

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“…However, additional GABA sources, such as neuron collaterals from the SNr or striatum, may also be involved. The increase in basal nigral Glu and GABA levels after SNc lesioning was larger in awake than in anesthetized animals (Windels et al, 2005), consistent with anesthetic effects on amino acid levels (Rozza et al, 2000;Windels and Kiyatkin, 2006).…”

Section: Discussionsupporting

confidence: 61%

Subthalamic Stimulation-Induced Forelimb Dyskinesias Are Linked to an Increase in Glutamate Levels in the Substantia Nigra Pars Reticulata

Boulet¹,

Lacombe²,

Carcenac³

et al. 2006

J. Neurosci.

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The neurobiological mechanisms by which high-frequency stimulation of the subthalamic nucleus (STN-HFS) alleviates the motor symptoms of Parkinson's disease (PD) remain unclear. In this study, we analyzed the effects of STN-HFS on motor behavior in intact or hemiparkinsonian rats (6-hydroxydopamine lesion of the substantia nigra pars compacta) and investigated the correlation between these effects and extracellular glutamate (Glu) and GABA levels, assessed by intracerebral microdialysis in the substantia nigra pars reticulata (SNr). STN-HFS at an intensity corresponding to the threshold inducing contralateral forelimb dyskinesia, increased Glu levels in the SNr of both intact and hemiparkinsonian rats. In contrast, STN-HFS at half this intensity did not affect Glu levels in the SNr in intact or hemiparkinsonian rats but increased GABA levels in hemiparkinsonian rats only. STN-HFS-induced forelimb dyskinesia was blocked by microinjection of the Glu receptor antagonist kynurenate into the SNr and facilitated by microinjection of a mixture of the Glu receptor agonists AMPA and NMDA into the SNr. These new neurochemical data suggest that STN-HFS-induced forelimb dyskinesia is mediated by glutamate, probably via the direct activation of STN axons, shedding light on the mechanisms of STN-HFS in PD.

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“…Rozza et al have shown that anesthesia induced by ketamine caused a significant decrease in the levels of glutamate, aspartate and glycine. Therefore, as we used two different anesthetic drugs (ketamine or isoflurane), we have a different impact of these phenomena and that can cause difference between uptake and washout kinetic [34,35]. There is also another limitation for the quantification of radioactivity in the brain; euthanasia was performed with overdose of anesthetic, so other studies using decapitation could allow us to compare disturbance caused by the overdose method.…”

Section: Limitationmentioning

confidence: 99%

Radiolabeling of [18F]-fluoroethylnormemantine and initial in vivo evaluation of this innovative PET tracer for imaging the PCP sites of NMDA receptors

Salabert

Fonta

Fontan

et al. 2015

Nuclear Medicine and Biology

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Influence of different anaesthetics on extracellular aminoacids in rat brain

Cited by 35 publications

References 20 publications

Glial uptake of neurotransmitter glutamate from the extracellular fluid studiedin vivoby microdialysis and¹³C NMR

Glial uptake of neurotransmitter glutamate from the extracellular fluid studiedin vivoby microdialysis and¹³C NMR

Subthalamic Stimulation-Induced Forelimb Dyskinesias Are Linked to an Increase in Glutamate Levels in the Substantia Nigra Pars Reticulata

Radiolabeling of [18F]-fluoroethylnormemantine and initial in vivo evaluation of this innovative PET tracer for imaging the PCP sites of NMDA receptors

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Influence of different anaesthetics on extracellular aminoacids in rat brain

Cited by 35 publications

References 20 publications

Glial uptake of neurotransmitter glutamate from the extracellular fluid studiedin vivoby microdialysis and13C NMR

Glial uptake of neurotransmitter glutamate from the extracellular fluid studiedin vivoby microdialysis and13C NMR

Subthalamic Stimulation-Induced Forelimb Dyskinesias Are Linked to an Increase in Glutamate Levels in the Substantia Nigra Pars Reticulata

Radiolabeling of [18F]-fluoroethylnormemantine and initial in vivo evaluation of this innovative PET tracer for imaging the PCP sites of NMDA receptors

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Product

Resources

About

Glial uptake of neurotransmitter glutamate from the extracellular fluid studiedin vivoby microdialysis and¹³C NMR

Glial uptake of neurotransmitter glutamate from the extracellular fluid studiedin vivoby microdialysis and¹³C NMR