I think it would be a job for a PS brushes with different blending modes and have a look here: http://www.icanbecreative.com/light-...photoshop.html
If you really want to do this in Illy do a search for "neon lightning effects in Illustrator" and do a mixture of this: http://www.dezineguide.com/tutorial/...e-illustrator/ with Arc tool and the Swirl tool with the blends in the above tutoial and transparency used in that tut. a long with gaussian blurs from the effects menu on the PS filter area. Also on the effects menu don't forget the effects in the Stylize part as you have "Drop Shadow, Feather, Inner & Outer Glows. If you have problems don't hesitate to come back and we will try to help. Just found this tut. which might help as well as it is about brushes used in Illy: http://design.tutsplus.com/tutorials...--vector-11237