TY - JOUR
T1 - Functional properties of neuronal nicotinic acetylcholine receptor channels expressed in transfected human cells
AU - Ragozzino, D.
AU - Fucile, S.
AU - Giovannelli, A.
AU - Grassi, F.
AU - Mileo, A. M.
AU - Ballivet, M.
AU - Alemà, S.
AU - Eusebi, F.
PY - 1997
Y1 - 1997
N2 - To study how subunit composition affects the functional properties of neuronal nicotinic acetylcholine receptors (nAChRs), we examined the behaviour of acetylcholine (ACh)-induced single-channel currents in human BOSC 23 cells transiently transfected with various subunit cDNA combinations. For all nAChRs examined (chick and rat α 3β 4, chick α 3β 2, α 4β 2, α 4β 4, α 7 and α 8), expression levels were high enough to allow measurements of acetylcholine-evoked whole-cell currents and nicotine-elicited Ca 2+ transients as well as the functional characterization of nAChR channels. Unitary acetylcholine-evoked events of α 8 nAChR had a slope conductance of 23 pS, whereas two conductance classes (19-23 and 32-45 pS) were identified for all other nAChR channels. The mean channel open times were significantly longer for homomeric α 7 and α 8 nAChRs (6-7 ms) than for heteromeric nAChRs (1-3 ms), with the exception of α 3β 4 nAChRs (8.4 ms for rat, 7 ms for chick). At least two species of heterologously expressed nAChRs (α 3β 4 and α 3β 2) exhibited single-channel characteristics similar to those reported for native receptors. The variety of nAChR channel conductance and kinetic properties encountered in human cells transfected with nAChR subunits contributes to the functional diversity of nAChRs in nerve cells.
AB - To study how subunit composition affects the functional properties of neuronal nicotinic acetylcholine receptors (nAChRs), we examined the behaviour of acetylcholine (ACh)-induced single-channel currents in human BOSC 23 cells transiently transfected with various subunit cDNA combinations. For all nAChRs examined (chick and rat α 3β 4, chick α 3β 2, α 4β 2, α 4β 4, α 7 and α 8), expression levels were high enough to allow measurements of acetylcholine-evoked whole-cell currents and nicotine-elicited Ca 2+ transients as well as the functional characterization of nAChR channels. Unitary acetylcholine-evoked events of α 8 nAChR had a slope conductance of 23 pS, whereas two conductance classes (19-23 and 32-45 pS) were identified for all other nAChR channels. The mean channel open times were significantly longer for homomeric α 7 and α 8 nAChRs (6-7 ms) than for heteromeric nAChRs (1-3 ms), with the exception of α 3β 4 nAChRs (8.4 ms for rat, 7 ms for chick). At least two species of heterologously expressed nAChRs (α 3β 4 and α 3β 2) exhibited single-channel characteristics similar to those reported for native receptors. The variety of nAChR channel conductance and kinetic properties encountered in human cells transfected with nAChR subunits contributes to the functional diversity of nAChRs in nerve cells.
KW - Ca transients
KW - Laser confocal microscopy
KW - Patch-clamp
KW - Single-channel conductance
KW - Transfection
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U2 - 10.1111/j.1460-9568.1997.tb01625.x
DO - 10.1111/j.1460-9568.1997.tb01625.x
M3 - Article
C2 - 9104590
AN - SCOPUS:0030989765
VL - 9
SP - 480
EP - 488
JO - European Journal of Neuroscience
JF - European Journal of Neuroscience
SN - 0953-816X
IS - 3
ER -