For the observations of both the membrane properties and the excitability on the nnfertilized eggs of female mice, changes of the membrane resistance and the membrane potential by hyerpolarizing current stimulation were recorded. As current-voltage relation was linear over the entire range (-180㎷∼＋60㎷), membrane resistance(Rm) was calculated from the amplitude of electrotonic potential to a given stimulus current. Also the presence of anode-break excitation was confirmed.
The results were as follows;
1. There was a linear relation between the membrane resistance and resting membrane potential, the expected input resistance was 61.4MΩ(resting membrane potential was －18.9±8.7㎷, mean±SD, n=30).
2. Transient depolarization with overshoot was generated just after hyperpolarizing current stimulus and showed the dependency of stimulus duration.
3. Transient depolarization lasted over 30㎳, amplitude of these depolarization was increased by high Ca^(++)(20mM) and inhibited by Ca^(++)-antagonist, Mn^(++).
4. From the above results, it was suggested that the unfertilized mouse egg showed the characteristics of the excitable cell.
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