holding cages with free access to food and water. These cages were lined initially with paper towels (i.e., first 24 hrs post-surgery) and then with regular pine shavings. When not subjected to conditioning procedures, animals were housed in these individual holding cages. No infections or surgery-related complications were observed. During conditioning, delivery of fluids was conducted by slipping the free end of the cannula inside a second polyethylene tube (PE 10), which in turn was connected to a Gilmont syringe (Barnant Co., Barrington, IL) mounted in a rotary microsyringe infusion pump (Kashinsky et al., 1990).
