I understand that when naive B cells are exposed to antigens, they become memory B cells, but what is the functional difference between the two? I've looked at the quite a few article on B cells, but none of them stated the difference clearly enough for me to understand.
The main difference is that memory B cells start an immune reaction much more effective and faster than naive B cells. The reaction is also specific towards the antigen.
The memory B cell has a specific membrane receptor for an antigen. It produces specific antibodies only when exposed to the antigen.
Tangye SG, Avery DT, Deenick EK, Hodgkin PD. Intrinsic differences in the proliferation of naive and memory human B cells as a mechanism for enhanced secondary immune responses. J. Immunol. 2003 Jan 15;170(2):686-94. PubMed PMID: 12517929.
Wikipedia contributors, "B cell," Wikipedia, The Free Encyclopedia, http://en.wikipedia.org/w/index.php?title=B_cell&oldid=612990219 (accessed June 26, 2014).
Naive B cells have not yet been trained by the immune system to recognize specific antigens -therefore the term "naive". Prior to antigen exposure, they must be trained in the bone marrow to recognize certain antigens.
Memory B cells, on the other hand, are formed after antigen exposure and clonal selection. As stated above, they have specific receptors for antigens and can produce antibodies.