Objective  To investigate the interaction between motoneurons (MNs) and Schwann cells (SCs) in co-culture in Transwell system.  Methods  MNs were harvested from SD rats at embryonic day 15; SCs were obtained from sciatic nerve of neonatal rats at day 1. MNs were cultured in the upper room of Transwell

while SCs in lower room (SCs pretreatment). The proliferation of SCs was detected by cell count and

3

H-TdR incorporation

and the level of BDN

F in SCs was detected by Western blot. The SCs pretreated or not and MNs pre-cultured in 1% O

2

for 4 h were co-cultured for 72 h

then the survival amount of MNs was detected by cell count and MTT.  Results  The proliferation index of SCs was (24 197.6±739.8) after co-culture with MNs in Transwell (group A) and (17 451.2±512.7) in its control group (group B) (P0.05)

and the level of BDNF in group A was higher than that in group B. The amount of hypoxic MNs and the value from MTT were (89.6±2.3)

(0.238 4±0.006 7) respectively after co-culture with pretreated SCs (group C)

and (66.4±4.8)

(0.196 2±0.005 9) in its corresponding control group (group D) (P0.05).  Conclusion  MNs can enhance the survival of SCs and their BDNF expression in non-contact culture manner

and these SCs have obvious protective effect on hypoxic MNs.