Uterine cells during labour. Computer-enhanced confocal light micrograph of cells from the outer lining of the uterus (myometrium) communicating with each other during labour. The cells' nuclei are light blue. One cell was injected with a blue dye, which it then passed to its neighbour. Myo- metrial cells only communicate in this way during labour, when they contract rhythmically to expel the baby from the uterus. Magnification unknown.