Objective       To determine the effect of cobalt chloride (CoCl

2

) post-conditioning on the spatial working memory in neonatal rats with hypoxic-ischemic induced brain damage (HIBD).       Methods       Sixty-six SD rats aged 7 d were randomly divided into sham operation group (N

n=16)

hypoxia-ischemia group (HI

n=18)

CoCl

2

administration immediately after surgery group (C1

n=14) and CoCl

2

administration 1 d after surgery group (C2

n=18). The left common carotid artery of rats were ligated after anesthesia followed by hypoxi

a. In the sham control group

the left common carotid artery was exposed but was not ligated or exposed to hypoxia. The brain tissues were harvested from the pups in each group at 1

2 and 7 d after ligation. HIF-1α expression was detected by Western blot analysis. At age of 7 weeks

pups of each group were trained to do the Morris water maze test to evaluate their spatial learning and memory abilities.       Results       HIF-1α expression was up-regulated in HI

C1 and C2 groups at post operation days 1 and 2

then decreased

and even not detectable in the former 2 groups at postoperative day 7

but detectable in C2 group. Morris water maze training revealed that the rats in C2 group had significantly shortened average latency time at 3 to 5 d

  and improved long-term reference memory compared with that in HI group (P0.05).       Conclusion       CoCl

2

improves and maintains the expression of HIF-1α in newborn rats after hypoxic-ischemic induced brain damage. Post-conditioning with CoCl

2

at 1 d after hypoxic-ischemic damage exerts neuroprotection and restores spatial working memory.