Voltage-dependent facilitation of Ca2+ entry in voltage-clamped, aequorin-injected molluscan neurons.
Voltage-clamp experiments were performed on giant neurons of the nudibranch Anisodoris nobilis injected with the Ca-sensitive photoprotein, aequorin. Depolarization beyond -10 to +5 m V produced an aequorin signal, the amplitude of which depended on the extracellular Ca2+ concentration, the amplitude of the depolarization, and its duration. In paired pulse experiments, the amplitude of the aequorin signal produced in response to the second of two identical depolarizing pulses was larger than that produced during the first, resulting from an increased entry of Ca2+ during the second pulse. The increment in Ca conductance inferred from the augmented signal during the second pulse was independent of Ca2+ influx during the first pulse but, instead, was related to the amplitude and duration of the first pulse.
D000331:Aequorin / Q000494:pharmacology* / Q000502:physiology; D000818:Animals; D001693:Biological Transport, Active; D002118:Calcium / Q000378:metabolism* / Q000494:pharmacology; D004553:Electric Conductivity; D004558:Electric Stimulation; D008974:Mollusca / Q000502:physiology*; D009474:Neurons / Q000187:drug effects / Q000502:physiology*; D011506:Proteins / Q000494:pharmacology*
D011506:Proteins; D000331:Aequorin; D002118:Calcium
J Physiol. 1971 Jul;216(2):503-12
4326997
J Physiol. 1971 Nov;218(3):709-55
5133953
J Physiol. 1974 Aug;241(1):91-110
4153582
Nat New Biol. 1973 Mar 28;242(117):113-5
4145281
J Physiol. 1975 Jul;249(2):211-39
1177091
J Physiol. 1976 Jan;254(1):129-51
1249721
Biochemistry. 1969 Oct;8(10):3991-7
4390576
Nature. 1970 Sep 26;227(5265):1356-7
4393938
Biochem Biophys Res Commun. 1967 Oct 26;29(2):229-34
4383681
Adv Biophys. 1973;4:71-102
4584559
Proc Natl Acad Sci U S A. 1975 Jan;72(1):187-90
235124
Proc Natl Acad Sci U S A. 1976 Aug;73(8):2918-22
183215
Nature. 1974 Aug 16;250(467):574-6
4845658
Proc Natl Acad Sci U S A. 1976 Jul;73(7):2520-3
1065905
Pharmacol Rev. 1976 MAR;28(1):1-93
781694
Science. 1975 Aug 15;189(4202):567-70
1145215
Brain Res. 1975 Jan 17;83(3):486-9
1111813
J Cell Comp Physiol. 1962 Jun;59:223-39
13911999
J Physiol. 1960 Jun;151:491-501
13824558
J Physiol. 1976 Nov;262(2):349-82
994042
J Physiol. 1976 Nov;262(2):319-48
994041