Red Currants

Do red currant bushes produce new growth via the existing bush or does it send up new shoots like raspberries and blackberrys? Thanks.

Mine are attempting both - shoots from the bottom and the branches from last  year are putting on a spurt. 

As I understand it, black currants are supposed to give multiple stems from below the ground, whereas red currants should not (why???). There should be one main stem and from above ground this should give a number of strong branches. The idea is then that the side branches of these should be maintained by yearly pruning to keep an open bush. They flower on older wood.

Maarten