Transient adenosine efflux in the rat caudate–putamen
Article first published online: 10 JAN 2008
© 2008 The Authors. Journal Compilation © 2008 International Society for Neurochemistry
Journal of Neurochemistry
Volume 105, Issue 4, pages 1253–1263, May 2008
How to Cite
Cechova, S. and Venton, B. J. (2008), Transient adenosine efflux in the rat caudate–putamen. Journal of Neurochemistry, 105: 1253–1263. doi: 10.1111/j.1471-4159.2008.05223.x
- Issue published online: 10 JAN 2008
- Article first published online: 10 JAN 2008
- Received November 12, 2007; revised manuscript received January 3, 2008; accepted January 3, 2008.
- electrical stimulation;
Adenosine is an endogenous byproduct of metabolism that regulates cerebral blood flow and modulates neurotransmission. Four receptors, with affinities ranging from nanomolar to micromolar, mediate the effects of adenosine. Real-time measurements are needed to understand the extracellular adenosine concentrations available to activate these receptors. In this study, we measured the subsecond time course of adenosine efflux in the caudate–putamen of anesthetized rats after a 1 s, high-frequency stimulation of dopamine neurons in the substantia nigra. Fast-scan cyclic voltammetry at carbon-fiber microelectrodes was used for simultaneous detection of adenosine and dopamine, which have different oxidation potentials. While dopamine was immediately released after electrical stimulation, adenosine accumulation was slightly delayed and cleared in about 15 seconds. The concentration of adenosine measured after electrical stimulation was 0.94 ± 0.09 μM. An adenosine kinase inhibitor, adenosine transport inhibitor, and a histamine synthetic precursor were used to pharmacologically confirm the identity of the measured substance as adenosine. Adenosine efflux was also correlated with increases in oxygen, which occur because of changes in cerebral blood flow. This study shows that extracellular adenosine transiently increases after short bursts of neuronal activity in concentrations that can activate receptors.