Glutamate-induced currents in acutely dissociated guinea pig locus coeruleus neurons.
To investigate the properties of L-glutamate (Glu) receptors in single locus coeruleus (LC) neurons at mature stage, we recorded the Glu-induced currents in the LC neurons acutely dissociated from adult guinea pigs, using the whole-cell patch-clamp technique. The concentration-current relationships show that Glu-induced currents in LC neurons might be predominantly mediated by non-NMDA receptors rather than NMDA receptors. The current-voltage relationship of NMDA or non-NMDA receptor-mediated currents indicated that both subtypes of the Glu-receptors operate non-selective cation channels, and that the NMDA receptor-operated channels but not the non-NMDA receptor-operated channels are permeable to Ca2+. These results suggest that in LC neurons, the normal excitatory neurotransmission may be mediated through non-NMDA receptors, and that NMDA receptors may be involved in intracellular signal transduction by their Ca2+ permeability.
Sengoku
A
A
Department of Physiology, Kobe University School of Medicine.
Mori
M
M
Okada
Y
Y
Kamidono
S
S
D000818:Animals; D002118:Calcium / Q000378:metabolism / Q000494:pharmacology; D004553:Electric Conductivity; D018691:Excitatory Amino Acid Antagonists / Q000494:pharmacology; D018698:Glutamic Acid / Q000494:pharmacology*; D006168:Guinea Pigs; D007473:Ion Channels / Q000502:physiology; D008125:Locus Coeruleus / Q000166:cytology* / Q000502:physiology; D008297:Male; D009474:Neurons / Q000502:physiology*; D018408:Patch-Clamp Techniques; D011810:Quinoxalines / Q000494:pharmacology; D017470:Receptors, Glutamate / Q000502:physiology; D016194:Receptors, N-Methyl-D-Aspartate / Q000502:physiology
D018691:Excitatory Amino Acid Antagonists; D007473:Ion Channels; D011810:Quinoxalines; D017470:Receptors, Glutamate; D016194:Receptors, N-Methyl-D-Aspartate; D018698:Glutamic Acid; C056723:FG 9041; D002118:Calcium