AIM  To investigate the effects of simulated weightlessness on hippocampal blood brain barrier (BBB) injury in rats and the countermeasure effect of intermittent artificial gravity.

  METHODS  Eight-week-old male SD rats were randomly divided into control group (CON), tail-suspension group (SUS) and intermittent artificial gravity group (IAG).

  RESULTS  Compared with the CON group, the overall distance traveled, total time in move, distance in center, the time of visit novel object as well as the discrimination index were significantly reduced in the SUS group (P<0.05, P<0.01), while the intermittent artificial partially alleviated the rats′ cognitive impairment caused by simulated weightlessness. Furthermore, according to the immunofluorescence, the density of blood vessel and vascular diameter were significantly decreased in SUS rats′ hippocampus (P<0.01). Meanwhile, Evans blue extravasation test confirmed that the permeability of blood-brain barrier in hippocampus of the SUS group was significantly increased, and which was also supported by elevated contents of Albumin (P<0.01). Western blotting results showed that occludin was decreased after 4-week simulated weightlessness in rats′ hippocampus, while the intermittent artificial significantly increased the experssion of occludin (P<0.05).

  CONCLUSION  the intermittent artificial alleviates the dysfunction of the BBB in the hippocampus induced by simulated weightlessness, and partly recovers cognitive dysfunction in rats.