Potentiation of N-methyl-D-aspartate-receptor-mediated currents detected using the excised patch technique in the hippocampal dentate gyrus.
The excised patch mode of the patch-clamp technique has been used to record isolated patch N-methyl-D-aspartate-receptor-mediated currents (patch NMDA-receptor-currents) evoked by electrical stimulation in the dentate gyrus of the hippocampal slice. The patch NMDA-receptor-currents were recorded by placing a patch of membrane isolated from the cell body in the inner molecular layer of the dentate gyrus and applying stimulation to the proximal commissural/associational pathway. The patch NMDA-receptor-currents, recorded at +40 mV in the presence of AMPA-receptor and GABAA-receptor antagonists, consisted of two to six summated unitary openings of NMDA-receptor channels, lasting several hundred milliseconds. Tetanic pathway stimulation evoked a rapid increase in the amplitude of the patch NMDA-receptor-currents which lasted for a period of at least 20 min following the tetanus. The study suggests that the potentiation of the patch NMDA-receptor-currents is due to either an increase in transmitter release, or alternatively, to the release of an extracellular messenger which directly enhances NMDA-receptor responsiveness.
O'Connor
J J
JJ
Department of Pharmacology and Therapeutics, Trinity College, Dublin 2, Ireland.
Wu
J
J
Rowan
M J
MJ
Anwyl
R
R
D000818:Animals; D018891:Dentate Gyrus / Q000502:physiology*; D004558:Electric Stimulation; D017774:Long-Term Potentiation / Q000502:physiology*; D018408:Patch-Clamp Techniques; D017729:Presynaptic Terminals / Q000502:physiology; D051381:Rats; D017208:Rats, Wistar; D016194:Receptors, N-Methyl-D-Aspartate / Q000502:physiology*
D016194:Receptors, N-Methyl-D-Aspartate