Metabotropic glutamate receptor mGluR5 is not involved in the early hemodynamic response

Activation of astrocytic metabotropic glutamate receptor 5 (mGluR5) is postulated to elicit calcium transients, triggering a chain of events that ultimately regulates cerebral blood flow by changing the tone of smooth muscle cells of nearby arterioles. Using concurrent in vivo optical imaging and determination of receptor occupancy with 11C-ABP688, we report here that blocking ∼80% of mGluR5 in vivo does not affect transient hemodynamic responses on brief whisker stimulations while transiently reducing neuronal activity as measured by voltage-sensitive dye imaging. Our results show that mechanisms other than activation of mGluR5 are required to trigger the initial hemodynamic response in normal physiological conditions.

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calcinaghi-2011.pdf

DOI

10.1038/jcbfm.2011.96

Researchers

Novella Calcinaghi

Renaud Jolivet

PD Dr. Dr. Matthias T Wyss

Simon M Ametamey

Fabrizio Gasparini

Alfred Buck

Prof. Dr. Bruno Weber