Oscillation of [Ca2+]i-linked K+ conductance in bullfrog sympathetic ganglion cell is sensitive to intracellular anions.
The intracellular free Ca2+ ([Ca2+]i) regulates the K+ conductance (GK) of the many types of cell membrane. The Ca2+ influx during an action potential activates this [Ca2+]i-linked GK in most neurones. In caffeine-treated sympathetic ganglion cells, however, Ca2+ released from an intracellular Ca2+ reservoir site analogous to the sarcoplasmic reticulum (SR) of the muscle (see ref. 12) causes activation of the GK, which results in slow oscillatory hyperpolarisations (caffeine hyperpolarisation, C-hyperpolarisation). Such a release of Ca2+ linked to the GK of the membrane seems important for understanding the role of the intracellular organelles in the control of membrane activities of a neurone. We report here the mechanism of the slow oscillatory hyperpolarisations recorded from the bullfrog sympathetic ganglion cell in Ringer solution. It is found that these hyperpolarisations are generated by a [Ca2+]i-linked GK system and are highly sensitive to anions in an intracellular recording electrode, probably to intracellular anions.
D000818:Animals; D000838:Anions / Q000502:physiology*; D001001:Anura; D002110:Caffeine / Q000494:pharmacology; D002118:Calcium / Q000502:physiology*; D002951:Citrates / Q000494:pharmacology; D004553:Electric Conductivity; D005728:Ganglia, Sympathetic / Q000502:physiology*; D066298:In Vitro Techniques; D008564:Membrane Potentials / Q000187:drug effects; D010507:Periodicity; D011188:Potassium / Q000502:physiology*; D011892:Rana catesbeiana
D000838:Anions; D002951:Citrates; D002110:Caffeine; D011188:Potassium; D002118:Calcium