 |
The Journal of Neuroscience, November 9, 2005, 25(45):10414-10419; doi:10.1523/JNEUROSCI.3660-05.2005
Previous Article | Next Article 
Neurobiology of Disease
Interactions between Metabotropic Glutamate 5 and Adenosine A2A Receptors in Normal and Parkinsonian Mice
Anil Kachroo,1
Lianna R. Orlando,1
David K. Grandy,2
Jiang-Fan Chen,1
Anne B. Young,1 and
Michael A. Schwarzschild1
1MassGeneral Institute for Neurodegenerative Disease, Department of Neurology, Massachusetts General Hospital, Boston, Massachusetts 02129, and 2Department of Physiology and Pharmacology, Oregon Health Sciences University, Portland, Oregon 97201
Evidence for heteromeric receptor complexes comprising adenosine A2A and metabotropic glutamate 5 (mGlu5) receptors in striatum has raised the possibility of synergistic interactions between striatal A2A and mGlu5 receptors. We investigated the role of striatal A2A receptors in the locomotor stimulant and antiparkinsonian properties of mGlu5 antagonists using complementary pharmacologic and genetic approaches. Locomotion acutely stimulated by the mGlu5 antagonist [2-methyl-6-(phenylethynyl)-pyridine (MPEP)] was absent in mGlu5 knock-out (KO) mice and was potentiated by an A2A antagonist KW-6002 [(E)-1,3-diethyl-8-(3,4-dimethoxystyryl)-7-methylxanthine], both in normal and in dopamine-depleted (reserpinized) mice. Conversely, the MPEP-induced motor response was markedly attenuated in single and double A2A and D2 receptor KO mice. In contrast, motor stimulation by a D1 dopamine agonist was not attenuated in the KO mice. The A2A receptor dependence of MPEP-induced motor stimulation was investigated further using a postnatal forebrain-specific conditional (Cre/loxP system) KO of the A2A receptor. MPEP loses the ability to stimulate locomotion in conditional KO mice, suggesting that this mGlu5 antagonist effect requires the postdevelopmental action of striatal A2A receptors. The potentiation of mGlu5 antagonist-induced motor stimulation by an A2A antagonist and its dependence on both D2 and forebrain A2A receptors highlight the functional interdependence of these receptors. These data also strengthen a rationale for pursuing a combinational drug strategy for enhancing the antiparkinsonian effects of A2A and mGlu5 antagonists.
Key words: metabotropic; adenosine; Parkinson's disease; knock-out; locomotion; G-protein-coupled receptor
Received April 26, 2005;
revised September 14, 2005;
accepted September 19, 2005.
This article has been cited by other articles:

|
 |

|
 |
 
M. Day, D. Wokosin, J. L. Plotkin, X. Tian, and D. J. Surmeier
Differential Excitability and Modulation of Striatal Medium Spiny Neuron Dendrites
J. Neurosci.,
November 5, 2008;
28(45):
11603 - 11614.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
T. Shindou, G. W. Arbuthnott, and J. R. Wickens
Actions of Adenosine A2A Receptors on Synaptic Connections of Spiny Projection Neurons in the Neostriatal Inhibitory Network
J Neurophysiol,
April 1, 2008;
99(4):
1884 - 1889.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
G. Burnstock
Physiology and Pathophysiology of Purinergic Neurotransmission
Physiol Rev,
April 1, 2007;
87(2):
659 - 797.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
D. Xiao, E. Bastia, Y.-H. Xu, C. L. Benn, J.-H. J. Cha, T. S. Peterson, J.-F. Chen, and M. A. Schwarzschild
Forebrain Adenosine A2A Receptors Contribute to L-3,4-Dihydroxyphenylalanine-Induced Dyskinesia in Hemiparkinsonian Mice
J. Neurosci.,
December 27, 2006;
26(52):
13548 - 13555.
[Abstract]
[Full Text]
[PDF]
|
 |
|
|