Objective      To determine the effect of beta-amyloid (Aβ) on the viability of neuroblastoma cells in vitro.       Methods      Neuroblastoma SH-SY5Y cells were divided into BSA group (0.5 mg/mL)

Aβ group (50 μg/mL Aβ

1-42

) and Aβ+p75-FC groups (50 μg/mL Aβ

1-42

+100 μg/mL p75-FC

fusion protein p75-FC is p75NTR extracellular domain of human IgG FC segment and able to competitively block p75NTR). All experimental groups were treated for 72 h. Crystal violet staining

was performed to examine the axonal growth of the SH-SY5Y cells. MTT assay was conducted to detect the viability of SH-SY5Y cells.       Results       The axon length in SH-SY5Y cells was significantly shorter in the Aβ group than the BSA group (42.83±14.98 vs 69.76±19.24 μm

P=0.003)

but there was no difference observed when co-cultured with p75-FC (axon length: 65.37±17.52 μm

P=0.600

compared with BSA group). MTT assay indicated that the cell viability was lower in the Aβ group than the BSA group (0.203±0.068 vs 0.428±0.094

P=0.002)

but there was no difference observed when co-cultured with p75-FC (0.447±0.103

P=0.768

compared with BSA group).       Conclusion      Aβ exerts a toxic effect on SH-SY5Y cells

which might be mediated by p75NTR.