Simultaneous measurements of conduction current, electron emission and electroluminescence in planar metal-insulator-metal gold structures have been performar. The development of the electrical characteristics of the devices from electroforming to sample degradation is reportar. Both electroluminescence and electron emission are observar as the samples electroform. Subsequent current-voltage cycles show peaks in the conduction current, electroluminescence and electron emission. A strong correlation is observar between the voltages at which the peaks in the conduction current and electroluminescence occur. There is also a subsidiary peak in the electron emission at higher values of appliar voltage corrresponding to the region of maximum negative differential resistance. The dependence of these effects on pressure has also been investigated.