Electrical activity of the infundibulum in relation to ovulation in the chicken.

Electrical activity was recorded from the smooth muscle layer of the infundibulum of unanaesthetized hens during the ovulation cycle. There were low-frequency isolated spike potentials throughout the cycle except for the period near ovulation. There were intermittent bursts of spike potentials about 1 h before ovulation and then an increased frequency of spike potentials near the time of ovulation. These may be related to the activity of the infundibulum engulfing the shed ovum. The frequency of electrical activity tended to decrease shortly after ovulation, but then increased again for a few hours. Premature ovulation induced by progesterone i.m. was associated with similar electrical changes.