Wanted - information on physiology of the human cortex cells

[Jyrki Alakuijala]

How often does the avarage human cortex neuron have action potentials?

How much energy is consumed in producing one action potential?

And propably a less important question:
How much energy is consumed in maintaining the neuron?

I need this information to estimate the brain power. 
If you have any references, please, include them. 

If I get any replies I will summarize to the net (with the estimation).
--
more at stekt.oulu.fi - Jyrki Alakuijala - Atraintie 6, 90550 Oulu, Finland
+358-81542334, male, 20 years, studying IT and working in the Univ. of Oulu