COMPARISON AMONG DIFFERENT APPROACHES FOR SAMPLING CEREBROSPINAL-FLUID IN RATS

Two approaches for time-resolved sampling of cerebrospinal fluid (CSF) in rats were compared regarding performance, reproducibility, and ext ent of the inevitable trauma caused by the implantation of a sampling tube, Several parameters were checked to evaluate the injury: blood ce ll contamination of CSF; concentrations in CSF of the cytosolic protei ns neuron-specific enolase (NSE) and S-100 (chiefly present in astrocy tes); blood-brain barrier leakage of a dye-protein complex; viability of nervous tissue cells as assessed by dye exclusion; light and electr on microscopy. In one sampling method, a tube was forced epidurally in to the cisterna magna via a hole in the calvarium, consistently damagi ng the meninges and the nervous tissue. When using the alternative sam pling method, the tube was instead affixed to the posterior atlanto-oc cipital membrane and connected with the cisterna magna via a hole in t he membrane. Such a procedure caused negligible damage, Both technique s induced an inflammatory response. We advocate the use of the second approach, i.e., to sample CSF via a hole in the atlanto-occipital memb rane, as the method of choice due to its high reproducibility, It is f airly rapid, and associated with a negligible injury. Copyright (C) 19 96 Elsevier Science Inc.