Ganglion cells from chick retina display multiple functional nAChR subtypes.
We have examined the properties of nicotinic acetylcholine receptors in embryonic chick retinal ganglion cells. Ganglion cells, identified according to morphological and physiological criteria, displayed spontaneous or induced action potentials. In 94/99 cells acetylcholine pulses evoked responses. In current clamp mode, acetylcholine provoked membrane depolarization and triggered action potentials. Under voltage clamp conditions, acetylcholine evoked inward currents that were readily blocked by d-tubocurarine. Antagonists specific for homomeric (alpha-bungarotoxin) and heteromeric (dihydro-beta-erythroidine) receptors revealed that ganglion cells express multiple functional receptor subtypes. These findings demonstrate that ACh modulates the electrical activity of these cells and is likely to mediate synaptic transmission. The presence of multiple receptor subtypes may contribute to processing and transmission of information in the retina.
Lecchi
M
M
Department of Physiology, Faculty of Medicine, CH-1211, CMU 1, rue M. Servet, Geneva 4, Switzerland.
Marguerat
A
A
Ionescu
A
A
Pelizzone
M
M
Renaud
P
P
Sommerhalder
J
J
Safran
A B
AB
Tribollet
E
E
Bertrand
D
D
D000109:Acetylcholine / Q000378:metabolism* / Q000494:pharmacology; D000200:Action Potentials / Q000187:drug effects / Q000502:physiology; D000818:Animals; D002038:Bungarotoxins / Q000494:pharmacology; D002454:Cell Differentiation / Q000187:drug effects / Q000502:physiology; D002642:Chick Embryo; D004079:Dihydro-beta-Erythroidine / Q000494:pharmacology; D018733:Nicotinic Antagonists / Q000494:pharmacology; D018408:Patch-Clamp Techniques; D011978:Receptors, Nicotinic / Q000187:drug effects / Q000378:metabolism*; D012160:Retina / Q000166:cytology / Q000196:embryology / Q000378:metabolism*; D012165:Retinal Ganglion Cells / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D009435:Synaptic Transmission / Q000187:drug effects / Q000502:physiology*; D014403:Tubocurarine / Q000494:pharmacology
D002038:Bungarotoxins; D018733:Nicotinic Antagonists; D011978:Receptors, Nicotinic; D004079:Dihydro-beta-Erythroidine; D000109:Acetylcholine; D014403:Tubocurarine