PT - JOURNAL ARTICLE AU - Blum, David AU - Galas, Marie-Christine AU - Pintor, Annita AU - Brouillet, Emmanuel AU - Ledent, Catherine AU - Muller, Christa E. AU - Bantubungi, Kadiombo AU - Galluzzo, Mariangela AU - Gall, David AU - Cuvelier, Laetitia AU - Rolland, Anne-Sophie AU - Popoli, Patrizia AU - Schiffmann, Serge N. TI - A Dual Role of Adenosine A<sub>2A</sub> Receptors in 3-Nitropropionic Acid-Induced Striatal Lesions: Implications for the Neuroprotective Potential of A<sub>2A</sub> Antagonists AID - 10.1523/JNEUROSCI.23-12-05361.2003 DP - 2003 Jun 15 TA - The Journal of Neuroscience PG - 5361--5369 VI - 23 IP - 12 4099 - http://www.jneurosci.org/content/23/12/5361.short 4100 - http://www.jneurosci.org/content/23/12/5361.full SO - J. Neurosci.2003 Jun 15; 23 AB - Reduction of A2A receptor expression is one of the earliest events occurring in both Huntington's disease (HD) patients and mice overexpressing the N-terminal part of mutated huntingtin. Interestingly, increased activity of A2A receptors has been found in striatal cells prone to degenerate in experimental models of this neurodegenerative disease. However, the role of A2A receptors in the pathogenesis of HD remains obscure. In the present study, using A2A-/- mice and pharmacological compounds in rat, we demonstrate that striatal neurodegeneration induced by the mitochondrial toxin 3-nitropropionic acid (3NP) is regulated by A2A receptors. Our results show that the striatal outcome induced by 3NP depends on a balance between the deleterious activity of presynaptic A2A receptors and the protective activity of postsynaptic A2A receptors. Moreover, microdialysis data demonstrate that this balance is anatomically determined, because the A2A presynaptic control on striatal glutamate release is absent within the posterior striatum. Therefore, because blockade of A2A receptors has differential effects on striatal cell death in vivo depending on its ability to modulate presynaptic over postsynaptic receptor activity, therapeutic use of A2A antagonists in Huntington's as well as in other neurodegenerative diseases could exhibit undesirable biphasic neuroprotective—neurotoxic effects.