A procedure for direct lumbar puncture in rats.

We have set out to establish a fast, simple and innocuous method for repeatedly obtaining cerebrospinal fluid (CSF) samples from rats that are undergoing different experimental procedures or suffering pathological conditions. Here, we report a method that has been optimized to repeatedly collect 30-50 microl of CSF in rats by direct lumbar puncture using a procedure that generally takes 15-20 min to perform and presents very little hazard to the animal. The rats are anaesthetized with isofluorane and placed on a board in such a way that the spine is curved at the level of the L3-L5 vertebrae. After performing a small incision in the skin of the back, a neonatal lumbar puncture needle is introduced into the intrathecal space and CSF is passively collected in the needle cup (facilitating maneuvers are described herein). Moreover, we have further adapted this method to permit the intrathecal delivery of pharmacological agents and cell suspensions. In such experiments, behavioral tests can be conducted 10-15 min after the intrathecal injection and the activity of the implanted cells can be assessed by sampling lumbar CSF at later times. Copyright 2002 Elsevier Science Inc.