A temporal analysis of naloxone's suppressant effect on drinking.

Licking activity was monitored in water deprived rats following various doses of naloxone. It was found that naloxone, at doses ranging from 0.01 to 10.0 mg/kg, had very little effect on initial drinking. However, naloxone did slow sustained drinking after 2 to 6 min into the bout, dependent upon dose. We takes these results to mean that naloxone is interfering with those processes which serve to sustain continued drinking throughout a drinking bout.