The ionic components of the current pulses generated by developing fucoid eggs.

摘要: Abstract Using a newly developed, extracellular vibrating electrode, we studied the ionic composition of current pulses which traverse developing Pelvetia embryo. External Na + , Mg 2+ or SO 4 2− are not needed for first 20 min pulsing. In fact, lowering external (or K ) actually stimulates Since tracer studies show that Ca entry is speeded by reduction, these findings suggest triggers A sevenfold reduction in Cl − raises pulse amplitudes 60%. Moreover, only major ion with an equilibrium potential near reversal potential. These facts efflux carries much “inward” current. We propose model pulsing increased within growing tip opens channels. The resulting slightly depolarizes membrane and thus drives balancing amount out. Thus, release KCl serve to relieve excess turgor pressure. By letting into tip, they should also strengthen transcytoplasmic electrical field postulated pull growth components toward this tip.