Adenosine modulates the striatal GABAergic inputs to the globus pallidus via adenosine A2A receptors in rats.
Previous studies have shown presynaptic modulation of adenosine A(2A) receptors for GABAergic synaptic transmission in the globus pallidus (GP). The pallidal A(2A) receptor-mediated modulation is caused by an action on the terminals of striatopallidal medium spiny neurons (MSNs) and/or axon collaterals of GP neurons. Herein, we examined the precise target neurons of the A(2A) receptor-mediated modulation. Activation of A(2A) receptors enhanced striatopallidal GABAergic transmission onto GP neurons, accompanied by a reduction in the paired-pulse facilitation, indicating the presynaptic contribution of A(2A) receptors at terminals of striatopallidal MSNs in the GP. Besides, no A(2A) receptor mRNA was detected in GP neurons by single-cell reverse transcription-polymerase chain reaction analysis, implying no contribution of axon collaterals of GP neurons to the A(2A) receptor regulation. These results demonstrate that the target neurons of adenosinergic modulation via A(2A) receptors in the GP are the striatopallidal MSNs.
Shindou
Tomomi
T
Pharmaceutical Research Institute, Kyowa Hakko Kogyo Co., Ltd., 1188 Shimotogari, Nagaizumi, Sunto, 411-8731, Shizuoka, Japan.
Richardson
Peter J
PJ
Mori
Akihisa
A
Kase
Hiroshi
H
Ichimura
Michio
M
D000241:Adenosine / Q000494:pharmacology*; D058908:Adenosine A2 Receptor Agonists; D000818:Animals; D003342:Corpus Striatum / Q000187:drug effects / Q000502:physiology*; D004558:Electric Stimulation / Q000379:methods; D005917:Globus Pallidus / Q000187:drug effects / Q000502:physiology*; D066298:In Vitro Techniques; D009434:Neural Pathways / Q000187:drug effects / Q000502:physiology; D051381:Rats; D043705:Receptor, Adenosine A2A / Q000502:physiology*; D009435:Synaptic Transmission / Q000187:drug effects / Q000502:physiology; D005680:gamma-Aminobutyric Acid / Q000502:physiology*
D058908:Adenosine A2 Receptor Agonists; D043705:Receptor, Adenosine A2A; D005680:gamma-Aminobutyric Acid; D000241:Adenosine