METHOD OF RECORDING CEREBROSPINAL-FLUID PRESSURE AT 3 ANATOMIC PLACESIN CONSCIOUS AND UNRESTRAINED ADULT WISTAR RATS

There does not appear to be a consensus on the normal values of cerebr ospinal fluid pressure (Pcsf) in rats because of the different conditi ons in which each experiment has been done. Anaesthesia, restraint or recordings from different anatomical places and the use of simultaneou s infusions could produce a great variability in the obtained results and because of that the average Pcsf in rats has been reported to be b etween 2 and about 18.5 cm H2O. The aim of this study is to provide ne w information about the normal values of Pcsf in adult, conscious rats by carrying out long-term measurements, for 3 consecutive days, from different anatomical places. Thirty male Wistar rats divided in three experimental groups of ten animals each were used. A catheter of silic one was implanted into the lateral ventricles in group I, the cisterna magna in group II, and the lumbar subarachnoid space in group III to record the Pcsf values. This catheter was attached to a swivel system to allow unrestrained and free behaviour in the rats. Mean values of n ormal Pcsf values were 13.03 +/- 0.73 cm H2O from the lateral ventricl es, 15.9 +/- 0.73 cm H2O from the cisterna magna, and 16.73 +/- 1.14 c m H2O from the lumbar subarachnoid space.