Dear Dunlian, there is differential treatment of corresponding author varying from country to country and organisation to organisation. But what I have perceived till date that its status is inferior to first author in any case. Frankly speaking, corresponding author's role also cant be under-estimated as the first author is first only upto article is published, but corresponding author is for the life time of article as and when communication related to that article arises. But we never put corresponding author as xxxxxxx et al, but it is always 1st author et al. I need more comments on this regard.

It is usually observed that First author is invariably the corresponding author, however in some cases where these two roles are performed by different persons, does the question arise as to what roles they are supposed to play besides communicating with the editor. I feel that the first author has a more important role because he has contributed the most to the article and usually leads the author list, but corresponding author is one who actually performs the functions of getting it published, answering the queries from reviewers, making suitable ammendments needed for making the manuscript worth publishing, so he has a more important role than the first author