TY - JOUR
T1 - A calcium-permeable channel activated by muscarinic acetylcholine receptors and InsP3 in developing chick ciliary ganglion neurons
AU - Distasi, Carla
AU - Di Gregorio, Federico
AU - Gilardino, Alessandra
AU - Lovisolo, Davide
N1 - Funding Information:
We thank D. Meandri and S. Bianco for technical assistance, and Dr. P. Zamburlin for help with the cultures. This work was financed by the Ministry of University and Scientific and Technological Research.
PY - 2002/6/12
Y1 - 2002/6/12
N2 - The electrical responses elicited by the muscarinic cholinergic pathway have been studied in cultured embryonic chick ciliary ganglion (CG) neurons. Neurons obtained from E7-E8 ganglia were maintained in serum-free medium for 1 to 3 days. Stimulation with 50 μM muscarine induced depolarizing responses in about 30% of the cells tested. In voltage clamp experiments at a holding potential of -50 mV, an inward current could be recorded in the same percentage of cells in response to muscarinic stimulation. In single channel experiments, with standard physiological solution in the pipette, muscarine transiently activated an inward conducting channel. Cell-attached recordings with 100 mM CaCl2 in the pipette provided evidence that muscarinic agonists can activate a cationic calcium-permeable channel. Two main conductance levels could be detected, of 2.3±0.6 and 5.6±0.6 pS, respectively. In excised patches, addition of 5-20 μM inositol 1,4,5-trisphosphate (InsP3) to the bath reactivated a channel that could be blocked by heparin and whose characteristics were very similar to those of the channel seen in response to muscarinic stimulation. A channel with similar properties has been previously shown to be activated by basic fibroblast growth factor (bFGF) and InsP3 in the same preparation.
AB - The electrical responses elicited by the muscarinic cholinergic pathway have been studied in cultured embryonic chick ciliary ganglion (CG) neurons. Neurons obtained from E7-E8 ganglia were maintained in serum-free medium for 1 to 3 days. Stimulation with 50 μM muscarine induced depolarizing responses in about 30% of the cells tested. In voltage clamp experiments at a holding potential of -50 mV, an inward current could be recorded in the same percentage of cells in response to muscarinic stimulation. In single channel experiments, with standard physiological solution in the pipette, muscarine transiently activated an inward conducting channel. Cell-attached recordings with 100 mM CaCl2 in the pipette provided evidence that muscarinic agonists can activate a cationic calcium-permeable channel. Two main conductance levels could be detected, of 2.3±0.6 and 5.6±0.6 pS, respectively. In excised patches, addition of 5-20 μM inositol 1,4,5-trisphosphate (InsP3) to the bath reactivated a channel that could be blocked by heparin and whose characteristics were very similar to those of the channel seen in response to muscarinic stimulation. A channel with similar properties has been previously shown to be activated by basic fibroblast growth factor (bFGF) and InsP3 in the same preparation.
KW - Calcium-permeable channel
KW - Chick embryo neuron
KW - Ciliary ganglion
KW - InsP3
KW - Muscarinic acetylcholine receptor
UR - http://www.scopus.com/inward/record.url?scp=0037067156&partnerID=8YFLogxK
U2 - 10.1016/S0167-4889(02)00206-9
DO - 10.1016/S0167-4889(02)00206-9
M3 - Article
SN - 0167-4889
VL - 1590
SP - 109
EP - 122
JO - Biochimica et Biophysica Acta - Molecular Cell Research
JF - Biochimica et Biophysica Acta - Molecular Cell Research
IS - 1-3
ER -