Function of non-NMDA receptors and NMDA receptors in synaptic responses to natural somatosensory stimulation in the ventrobasal thalamus.
Sensory synaptic responses of rat ventrobasal thalamus neurones were challenged with iontophoretic applications of the excitatory amino acid antagonists CNQX and CPP. CNQX, applied with currents which were selective for non-NMDA receptors, antagonised responses of VB neurones to both 10 ms and 2000 ms air jet stimulation of the peripheral receptive field. In contrast, CPP only antagonised the latter type of response. These results suggest a differential involvement of excitatory amino acid receptors in sensory synaptic transmission to the ventrobasal thalamus, with an initial synaptic component being mediated by non-NMDA receptors (including kainate receptors), and a further NMDA receptor-mediated component being manifested upon maintained sensory stimulation. The expression of this latter component appears to be largely dependent upon the integrity of the non-NMDA receptor-mediated component.
Salt
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Department of Visual Science, Institute of Ophthalmology, London, UK.
Eaton
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D018750:6-Cyano-7-nitroquinoxaline-2,3-dione; D000200:Action Potentials / Q000187:drug effects; D000596:Amino Acids / Q000494:pharmacology; D000818:Animals; D000927:Anticonvulsants / Q000494:pharmacology*; D008297:Male; D009475:Neurons, Afferent / Q000187:drug effects / Q000502:physiology*; D010812:Physical Stimulation; D010879:Piperazines / Q000494:pharmacology*; D011810:Quinoxalines / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains; D017459:Receptors, Amino Acid; D011956:Receptors, Cell Surface / Q000037:antagonists & inhibitors / Q000502:physiology*; D016194:Receptors, N-Methyl-D-Aspartate; D017981:Receptors, Neurotransmitter / Q000037:antagonists & inhibitors / Q000502:physiology*; D013787:Thalamic Nuclei / Q000187:drug effects / Q000502:physiology*
D000596:Amino Acids; D000927:Anticonvulsants; D010879:Piperazines; D011810:Quinoxalines; D017459:Receptors, Amino Acid; D011956:Receptors, Cell Surface; D016194:Receptors, N-Methyl-D-Aspartate; D017981:Receptors, Neurotransmitter; D018750:6-Cyano-7-nitroquinoxaline-2,3-dione; C050592:3-(2-carboxypiperazin-4-yl)propyl-1-phosphonic acid