Metabotropic glutamate receptors potentiate responses to NMDA and AMPA from layer V cells in rat visual cortex.
1. With the use of whole cell recordings of layer V cells from slices of rat visual cortex, we demonstrate a potentiation of the response to N-methyl-D-aspartate (NMDA) by the metabotropic glutamate agonist (1S,3R)-1-Amino-1,3-cyclopentanedicarboxylic acid. This potentiation occurs within a few seconds and lasts a few minutes. 2. The potentiation is seen with tetrodotoxin in the perfusion solution, but is abolished by guanosine 5'-O-(2-thiodiphosphate) in the pipette solution, showing that it is a postsynaptic phenomenon. The potentiation is also abolished by alpha-methyl-4-carboxyphenylglycine in the bath solution, confirming that it is due to metabotropic glutamate receptors. 3. In 29 of 31 cases tested, the response to alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid was also potentiated, and the potentiation remained in the presence of the NMDA antagonist D-2-amino-5-phosphonovalerate.
Wang
X F
XF
Department of Ophthalmology and Visual Science, Yale University Medical School, New Haven, Connecticut 06520-8061, USA.
Daw
N W
NW
D000818:Animals; D003515:Cycloleucine / Q000031:analogs & derivatives / Q000494:pharmacology; D004357:Drug Synergism; D018690:Excitatory Amino Acid Agonists / Q000494:pharmacology*; D066298:In Vitro Techniques; D007478:Iontophoresis; D016202:N-Methylaspartate / Q000494:pharmacology / Q000502:physiology*; D018408:Patch-Clamp Techniques; D051381:Rats; D018094:Receptors, Metabotropic Glutamate / Q000502:physiology*; D016194:Receptors, N-Methyl-D-Aspartate / Q000502:physiology; D014793:Visual Cortex / Q000502:physiology*; D018350:alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid / Q000494:pharmacology*
D018690:Excitatory Amino Acid Agonists; D018094:Receptors, Metabotropic Glutamate; D016194:Receptors, N-Methyl-D-Aspartate; D003515:Cycloleucine; C036361:1-amino-1,3-dicarboxycyclopentane; D016202:N-Methylaspartate; D018350:alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid