The effect of naloxone on schedule-induced and other drinking.

A dose-response study of the effect of naloxone on schedule-induced drinking confirmed that this type of drinking is resistant to the opiate antagonist at doses which depressed drinking induced by water-deprivation, hypertonic saline and salbutamol. Naloxone also failed to reduce intake of saline solution in the presence of scheduled food presentation. The findings support the suggestion that schedule-induced drinking is regulated by a system of neural control which differs from that involved in deprivation and other forms of drinking. It would appear that opiate receptors do not play a part in the regulation of schedule-induced drinking.