Abstract: Objective To study the liquefaction in the cystic cavity of cerebral infarction and the blood supply in the wall to explore whether it is suitable for neural stem cell transplantation. Methods A total of 20 male Sprague-Dawley rats were established middle cerebral artery occlusion (MCAO) model. They were observed the formation of cystic cavity three, ten and 21 days after modeling with MRI, and the coordinates of cystic cavity and lateral ventricle were recorded. Intracystic fluid and cerebrospinal fluid were extracted from the rats with cavities for mass spectrometry. Frozen sections of the brains were stained with HE and immunofluorescence agglutinin and observed. Results The cystic cavity in the infarction area became stable 21 days after modeling, which was composed of the brain tissue and the pia matter. There was no cellular structure in the center of the cystic cavity. The wall of the cystic cavity was partly composed of the pia matter. There were a large number of cells at the junction between the center of the cystic cavity and the meninges. Blood vessels distributed around the cystic cavity, similar with those in unaffected side. A total of 36 different molecules were screened out, in which 31 increased and five decreased. For the top ten molecules, most of them positively benefited stem cell transplantation, including anti-inflammatory, anti-tumor and promoting the survival of nerve cells. However, they did not liked to promote neural stem cells differentiating into neurons, but glial cells. Conclusion As a relatively closed fluid space, the cystic cavity formed in the chronic cerebral infarction can provide basic conditions for neural stem cell transplantation. However, relevant molecular components in the microenvironment mostly promote the differentiation of neural stem cells into glial cells.

Key words: cerebral infarction, cystic cavity, microenvironment, cerebrospinal fluid, mass spectrometry, differential factors