select the item, go to the Material Room, ..in the top right corner of the material editor, make sure the 'object/ item & material is selected that u want to make glo....then click on the 'advanced' tab...find the 'specular' (or ambient as mentioned in earlier post)..press on the value (number box) & drag to the right, (or just type in a number)...u can start with 5 or 10,, u should see the item's mat get brighter in the mat preview, but do a testrender ..u can also change the color of either by clicking on their color boxes

 

don't know which version of Poser u have, but there's also GlowWorm & Shader Spider, both for Poser 7

http://www.daz3d.com/i/3d-models/-/glowworm?item=3946

http://www.daz3d.com/i/3d-models/-/shaderspider?item=3551&spmeta=rl

 

if u need any more info lmk