Tolerance to the effects of daily nicotine on rat bar pressing behavior for water reinforcement

The effects of daily nicotine tartrate given IP in a dose of 0.25 mg/kg twice a day for 15 days was studied on bar pressing behavior for water reinforcement in the rat. A modified FR_{1 5} schedule was used. Nicotine injections caused an initial disruption of bar pressing behavior with rapid tolerance development. Antidiuretic hormone (5–10 units/kg, SC) administration also suppressed water drinking behavior after an initial latency in contrast to the effects of nicotine. It is concluded that tolerance occurs to daily nicotine administration.