BDNF and neuroblastoma: The SH-SY5Y neuroblastoma cells were incubated with E2, CHOL, BDNF, or RA or with their combinations (RE, RB, RC, RCB and RCBE) and stained at 10 DIV with AM1-43, a fluorescent styryl dye (a nerve terminal probe) with the presence of depolarizing high K+-Tyrode solution.