| Abstract: | The mean membrane potentials of cellular elements were measured during the passage of a glass microelectrode through cortical tissue in fetuses and newborn guinea pigs. The average value of membrane potential increases in fetuses after the 47th day of gestation from 7.6 mV to 28.1 mV in newborn guinea pigs. The developmental changes in histograms of individual values correspond to the increase in mean value. The membrane potentials are sensitive to brain hypoxia following cord clamping only after the 62nd day of gestation. In term fetuses, cord clamping is followed by regular lung ventilation and by the slow gradual increase of mean value in membrane potentials. The development of the mean membrane potential of cortical elements correlates well with the development of the cortical steady potential. |
