A novel modified method and its confirmation of injection into CSF via the cerebellomedullary cistern in mice

Journal of Cerebral Blood Flow & Metabolism (2009) 29, S213?S257

 

A novel modified method and its confirmation of injection into CSF via the cerebellomedullary cistern in mice浙江大学医学院附属邵逸夫医院神经外科陈毅力

Y. Chen(陈毅力)^1,2, A. Ito¹ and N. Saito¹

1Department of Neurosurgery, Faculty of Medicine, University of Tokyo, Tokyo, Japan;

2Department of Neurosurgery, Sir Run Run Shaw Hospital, Medical College of Zhejiang University, Hangzhou, China

Background and aims: Central administrations of delivering drugs and chemotherapeutic agents are very difficult to be applied in mice related to the small size. Injection into the cerebellomedullary (CM) cistern is one of the options of central administrations. As its location is relatively fixed, it has potent advantantage than intraventricular administration under some pathological state, especially in supratentorial lesion models. We aimed to obtain a more accurate method for Injection into the CM cistern in mice. Methods: We modified the method firstly introduced by Ueda et al. We choose the prone position with nape elevation and extension under inhalation anesthesia. The nape of the neck was incised at the midline. The hand-made curved tip of a 27 gauge dental needle was inserted into the cleft between the occiput and the atlas vertebra through the muscles and ligaments, being warranted on the line between sagittal suture and midline of nape. A volume of 6 ml methylene blue aqueous solution was injected slowly into the CM cistern to check accuracy. Mice were sacrificed 1 h(n = 8), 6 h (n=6) or 24h (n=6) after injection. Results: Twenty C57BL/6 mice were used to check our modified method and all succeeded without any serious vital or neurological deficits. The dye in the injection place and the intracranial distribution (CM cistern, ventral cisterns, trigerminal nerve and optic nerve roots) could be recognized within 6 h after injection. The dye was disappeared in all places while being checked 24 h after injection. Conclusions: Our new method of injection into CM cistern is easy to be grasped and can become a common method to examine chemical substances’ effects on central nerve system in mice. It is no use for dye injection along with the drug procedure for confirmation if mice were sacrificed beyond 6 h after injection.