TY - JOUR
T1 - The involvement of metabotropic glutamate receptors in long-term depression of N-methyl-d-aspartate receptor-mediated synaptic potential in the rat hippocampus
AU - Yi, Pei Lu
AU - Chang, Fang Chia
AU - Tsai, Jing Jane
AU - Hung, Chen Road
AU - Gean, Po Wu
PY - 1995/2/13
Y1 - 1995/2/13
N2 - The frequency-dependent long-term modifications of pharmacologically isolated N-methyl-d-aspartate (NMDA) receptor-mediated excitatory postsynaptic potential (EPSPNMDA) was studied. Intracellular recordings were obtained from CA1 cells of rat hippocampal slices and in the presence of 6-cyano-7-nitroquinoxaline-2,3-dione (10 μM) and bicuculline (20 μM) which block non-NMDA and GABAA receptors, respectively. Low-frequency stimulation at 5 Hz resulted in a long-term depression (LTD) of EPSPNMDA in 12 of 17 cells. However, when the stimulus frequency was increased to 30 Hz, a long-term potentiation (LTP) of EPSPNMDA was observed in 7 out of 9 cells. The LTD was not affected by pretreating the slices with okadaic acid (0.5-1 μM) suggesting that activation of endogenous protein phosphatase is not responsible for this process. In the presence of l-2-amino-3-phosphonopropionic acid (50 μM) or (RS)-α-methyl-4-carboxyphenylglycine (200 μM), 5 Hz tetanization resulted in LTP instead of LTD. These results suggest that activation of metabotropic glutamate receptor (mGluR) is necessary for the induction of EPSPNMDA LTD and blockade of mGluR unmasks a LTP.
AB - The frequency-dependent long-term modifications of pharmacologically isolated N-methyl-d-aspartate (NMDA) receptor-mediated excitatory postsynaptic potential (EPSPNMDA) was studied. Intracellular recordings were obtained from CA1 cells of rat hippocampal slices and in the presence of 6-cyano-7-nitroquinoxaline-2,3-dione (10 μM) and bicuculline (20 μM) which block non-NMDA and GABAA receptors, respectively. Low-frequency stimulation at 5 Hz resulted in a long-term depression (LTD) of EPSPNMDA in 12 of 17 cells. However, when the stimulus frequency was increased to 30 Hz, a long-term potentiation (LTP) of EPSPNMDA was observed in 7 out of 9 cells. The LTD was not affected by pretreating the slices with okadaic acid (0.5-1 μM) suggesting that activation of endogenous protein phosphatase is not responsible for this process. In the presence of l-2-amino-3-phosphonopropionic acid (50 μM) or (RS)-α-methyl-4-carboxyphenylglycine (200 μM), 5 Hz tetanization resulted in LTP instead of LTD. These results suggest that activation of metabotropic glutamate receptor (mGluR) is necessary for the induction of EPSPNMDA LTD and blockade of mGluR unmasks a LTP.
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U2 - 10.1016/0304-3940(95)11264-W
DO - 10.1016/0304-3940(95)11264-W
M3 - Article
C2 - 7753492
AN - SCOPUS:0028878157
SN - 0304-3940
VL - 185
SP - 207
EP - 210
JO - Neuroscience Letters
JF - Neuroscience Letters
IS - 3
ER -