I don't know anything about your particular bulb, but as far as I do know, most gas-discharge bulbs require an initial high voltage strike to ionize the gas, which can be followed by a lower maintaining voltage. Neon bulbs and nixie tubes work this way -- they become essentially constant voltage zeners once ionized. A series resistor typically provides the current limiting and drops the excess voltage.

I think other forms of discharge lamps work in a similar fashion. However, some sort of electronic ballast is used and is more efficient than using a resistor.