Non-NMDA-mediated transmission of somatosensory-evoked potentials in the rat thalamus.
Somatosensory-evoked potentials (SEPs) were recorded from the somatosensory cortex of pentobarbital-anesthetized rats, in response to single electrical stimulation of the contralateral forelimb. The effects of microapplication of the selective N-methyl-D-aspartate (NMDA) antagonist, (-)-2-Amino-7-phosphonoheptanoate (AP7), and of the specific non-NMDA antagonist, 6,7-Dinitro-quinoxaline-2,3-dione (DNQX), in the ventrobasal thalamic nucleus on the amplitudes and latencies of cortical potentials were measured. The injection of DNQX resulted in a decrease in amplitude and an increase in the latency of cortical SEPs. These effects were a) dose dependent over the range 0.1 to 1.0 nmol, b) specific for non-NMDA receptors, and c) site specific. In contrast, microapplications of AP7 did not affect the SEPs. The present findings support the hypothesis that non-NMDA receptors in the ventrobasal thalamic nucleus are involved in the transmission of cortical SEPs.
Block
F
F
Max-Planck-Institute for Experimental Medicine, Göttingen, Germany.
Schwarz
M
M
Sontag
K H
KH
D000758:Anesthesia; D000818:Animals; D000927:Anticonvulsants / Q000494:pharmacology; D004558:Electric Stimulation; D005073:Evoked Potentials, Somatosensory / Q000187:drug effects / Q000502:physiology*; D005998:Glycine / Q000494:pharmacology; D007051:Ibotenic Acid / Q000031:analogs & derivatives / Q000494:pharmacology; D008297:Male; D016202:N-Methylaspartate / Q000502:physiology*; D011810:Quinoxalines / Q000008:administration & dosage / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D013003:Somatosensory Cortex / Q000187:drug effects; D013238:Stereotaxic Techniques; D009435:Synaptic Transmission / Q000187:drug effects / Q000502:physiology*; D013787:Thalamic Nuclei / Q000187:drug effects / Q000502:physiology*; D018350:alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid
D000927:Anticonvulsants; D011810:Quinoxalines; D007051:Ibotenic Acid; C056723:FG 9041; D016202:N-Methylaspartate; D018350:alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid; D005998:Glycine