The most common locution is "to be in a vein" for "inspired, with genius"; but this seems like a way of saying "to be hot" ("up, or angry"). See vein ("inspiration") ; also inflamed vein, by some enlargement.
WALK WITH THE VENA Have great sexual appetite, need to have sex as a product of a long abstinence. Some synonyms, words or similar expressions may be walking with the rich, having the accumulated kino, walking eagerly