The intercellular signals refer to the signals that conduct the signals from one cell to another, and these signals conduct messages within the cell. The intercellular signals may not be mediated via the gap junctions.
The signaling molecules often exhibit a receptor on the cells, where the binding of the molecules takes place and leads to stimulation of the cell. The signaling molecules can also get inside the cells with the help of facilitated diffusion and active transport. So, this kind of conduction cannot mediate via gap junctions.
Thus, the intracellular signals that do not pass through direct associations between cells like gap junctions, either enter the cell through the membrane or combine with the receptor molecule present on the surface of the cell.