Synaptic potentials recorded from sea anemone muscle cells in situ
✍ Scribed by K. Cho; I.D. McFarlane
- Publisher
- John Wiley and Sons
- Year
- 1996
- Tongue
- English
- Weight
- 634 KB
- Volume
- 44
- Category
- Article
- ISSN
- 0360-4012
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✦ Synopsis
Three pulse types
, A, B,
and
C
, can be recorded from column ring preparations of the sea anemone CaZZi- actis parasitica (Couch). Lucifer Yellow injection confirmed that the recording sites are intracellular in endodermal myoepithelial cells. Type C pulses are spontaneously active depolarizing pulses, arising from a resting potential of around -60 mV, and are usually <5 mV in amplitude. When the cells were voltage-clamped these pulses reversed at around 0 mV membrane potential; therefore, we conclude that they are synaptic potentials. In some cells an increase in frequency of type C pulses accompanied contraction of the circular muscle field. Inward currents in these myoepithelial cells are carried by Ca", and although Na+ -free solutions did not affect inward currents they did eliminate type C pulses, i.e., these synaptic potentials may result from activity of Na+dependent nerve cells.