Skip to ContentSkip to Navigation
About us Latest news News News articles

Monitoring extracellular glutamate in the rat brain by microdialysis and microsensors: pharmacological applications

01 April 2011

PhD ceremony: Ms. M. Evering-van der Zeyden, 16.15 uur, Academiegebouw, Broerstraat 5, Groningen

Title: Monitoring extracellular glutamate in the rat brain by microdialysis and microsensors: pharmacological applications

Promotor(s): prof. B.H.C. Westerink

Faculty: Mathematics and Natural Sciences

 

The aim of the thesis of Miranda Evering-van der Zeyden was to investigate the origin of extracellular glutamate as detected by microdialysis or microsensors in the brain of the rat. Extracellular L-glutamate, an important and abundant excitatory neurotransmitter in the brain, is believed to be derived from both glial and synaptic sources.

First it she has investigated whether NMDA glutamate receptors localized on the somatodendritic sites of mesolimbic dopamine neurons can be used as a functional NMDA model. To that end a dual-probe microdialysis system was used. The NMDA receptors localized on dopamine neurons in the ventral tegmental area (VTA) were influenced by infusing glutamatergic compounds and the activity of these neurons was determined by recording dopamine in the ipsilateral nucleus accumbens (NAc). Effect of glutamatergic excitation was clearly detectable as infusions of NMDA increased dopamine levels to about 150% of controls. However, the model displays a limited sensitivity when a decrease in NMDA-receptor activity needs to be detected

Next the dual-probe model was used by Evering-van der Zeyden to apply glutamatergic pharmacological active compounds to dopamine neurons in the VTA. Her results of these experiments displayed a clear mismatch between the extracellular levels of glutamate, detected in microdialysis samples of the VTA, and the activity of dopaminergic cells in the VTA as measured by dopamine release in the NAc. These observations suggest that care should be taken to relate glutamate in microdialysates to ‘neuronal glutamatergic activity’ in the brain. However, during certain pharmacological conditions, a minor part of glutamate sampled by microdialysis, might be directly related to synaptic events.

 

Last modified:13 March 2020 01.12 a.m.
printView this page in: Nederlands

More news

  • 07 August 2020

    Virus assembly has been filmed

    Scientists in Groningen and Madrid have managed to capture unique images of the first steps of virus assembly. By using a very fast scanning probe microscope, they were able to film how HIV proteins begin to form a virus. It appears that the virus...

  • 30 July 2020

    Restanten van een vergeten bolhoop ontdekt rond de Melkweg

    Restanten van een vergeten bolhoop ontdekt rond de Melkweg

  • 28 July 2020

    Populaties trekvissen wereldwijd met driekwart geslonken

    Een nieuw internationaal onderzoek laat zien dat bestanden van trekkende zoetwatervissen zoals zalm, paling en houting in de afgelopen vijftig jaar met 76% zijn afgenomen. In Europa is de afname met 93% het grootste. De trekvissen hebben het vooral...