Reversal potential of the end-plate currents and potassium feedback at the neuromuscular synapse
✍ Scribed by D. P. Matyushkin; I. I. Krivoj; I. A. Shabunova
- Publisher
- John Wiley and Sons
- Year
- 1984
- Tongue
- English
- Weight
- 686 KB
- Volume
- 11
- Category
- Article
- ISSN
- 0360-4012
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✦ Synopsis
The experiments were carried out at the neuromuscular junction of the frog. Ere, of epc was estimated by two methods-extrapolation and interpolation. In K+enriched solution Ere, obtained by linear extrapolation from high-mp region changed according to the Takeuchi equation. The behavior of Ere, obtained by interpolation was better described by the Goldman-Hodgkin-Katz equation. Under the change of the nerve stimulation frequency from 0.5 to 5O/sec, the positive shift of E, , estimated by both methods was observed. This indicates K+ accumulation in active synaptic segments during activity. The elimination of the potassium current of epc by clamping of mp at the -130 mV level resulted in the lowering of facilitation under paired nerve stimulation (20 msec interval) and in the decrease of the rate of facilitation under 50isec frequency stimulation. The data support the presence of antidromic Kt action in the neuromuscular synapse.