Rapid intracerebroventricular injection assisted by an automatic syringe.

Rapid intracerebroventricular (icv) injections in the conscious mouse are described, using a small volume gas-tight syringe with repeating dispenser device (Hamilton Bonadoz, Switzerland). The device gives reproducibility within 2% of chosen volume, while facilitating rapid icv injections to groups of animals. The technique is used to demonstrate in the mouse the antinociceptive activity of clonidine, using the tail-immersion test.