Brain in irregular patterns; other neurons are quiet most of the time, but occasionally emit a burst of action potentials. Axons transmit signals to other neurons by means of specialized junctions called synapses. A single axon may make as many as several thousand synaptic connections with other cells. When an action potential, traveling along an axon, arrives at a synapse, it causes a chemical called a neurotransmitter to be released. The neurotransmitter binds to receptor molecules in the membrane of the target cell. Synapses are the key functional elements of the brain. The essential function of the brain is cell-to-cell communication,
Signals, Crane and Subway, Charters Towers railway station the signal box, although electrical or hydraulic operation could be used for more distant signals. At night, lights were necessary, and kerosene lamps with movable coloured spectacles displayed different colours, including green (proceed), yellow (prepare to find next signal red), and red (stop). Later, electrical coloured lights were used. Smaller points indicator signals, which confirmed whether or not points had been switched, could be used for shunting within a railway yard, and the most common form was the rotating disk signal. These could also contain a kerosene lamp for night operation. To coordinate signals so that is impossible to give