Suboccipital puncture of guinea pigs.

Cisternal cerebrospinal fluid (CSF) was tapped from anaesthetized guinea pigs by an improved technique. This method allowed repeated weekly punctures of the same animal without any cellular or neurochemical changes in CSF or changes in behaviour. About 60% of the punctures produced enough CSF (30-330 microliters) with no or a sufficiently low blood contamination for neurochemical analysis. The CSF space in the spinal canal, cisterna magna and basal cisterns was demonstrated by myelography.