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NR2A and NR2B subunit containing NMDA receptors differentially regulate striatal output pathways
Author(s) -
Fantin Martina,
Marti Matteo,
Auberson Yves P.,
Morari Michele
Publication year - 2007
Publication title -
journal of neurochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.75
H-Index - 229
eISSN - 1471-4159
pISSN - 0022-3042
DOI - 10.1111/j.1471-4159.2007.04966.x
Subject(s) - globus pallidus , nmda receptor , substantia nigra , striatum , basal ganglia , glutamate receptor , chemistry , neuroscience , medium spiny neuron , biology , medicine , endocrinology , dopamine , receptor , central nervous system , biochemistry , dopaminergic
Triple probe microdialysis was employed to investigate whether striatal NR2A and NR2B subunit containing NMDA receptors regulate the activity of striato‐pallidal and striato‐nigral projection neurons. Probes were implanted in the striatum, ipsilateral globus pallidus and substantia nigra reticulata. Intrastriatal perfusion with the NR2A subunit selective antagonist ( R )‐[( S )‐1‐(4‐bromo‐phenyl)‐ethylamino]‐(2,3‐dioxo‐1,2,3,4‐tetrahydroquinoxalin‐5‐yl)‐methyl]‐phosphonic acid (NVP‐AAM077) reduced pallidal GABA and increased nigral glutamate (GLU) release whereas perfusion with the NR2B subunit selective antagonist ( R ‐( R *, S *)‐α‐(4‐hydroxyphenyl)‐β‐methyl‐4‐(phenylmethyl)‐1‐piperidinepropanol (Ro 25‐6981) reduced nigral GABA and elevated striatal and pallidal GLU release. To confirm that changes in GABA levels were because of blockade of (GLUergic‐driven) tonic activity of striatofugal neurons, tetrodotoxin was perfused in the striatum. Tetrodotoxin reduced both pallidal and nigral GABA release without changing GLU levels. To investigate whether striatal NR2A and NR2B subunits were also involved in phasic activation of striatofugal neurons, NVP‐AAM077 and Ro 25‐6981 were challenged against a NMDA concentration able to evoke GABA release in the three areas. Both antagonists prevented the NMDA‐induced striatal GABA release. NVP‐AAM077 also prevented the NMDA‐induced surge in GABA release in the globus pallidus, whereas Ro 25‐6981 attenuated it in the substantia nigra. We conclude that striatal NMDA receptors containing NR2A and NR2B subunits preferentially regulate the striato‐pallidal and striato‐nigral projection neurons, respectively.