Related Experiment Video
Updated: Oct 18, 2026

A Method for Evaluating the Reinforcing Properties of Ethanol in Rats without Water Deprivation, Saccharin Fading or Extended Access Training
Published on: January 29, 2017
Orexins/hypocretins regulate drinking behaviour
1Department of Pharmacology, Institute of Basic Medical Sciences, University of Tsukuba, Tsukuba, Japan.
Abstract:
Orexin/hypocretins are recently identified neuropeptides which regulate feeding behaviour. We found orexins increased water intake when administrated intracerebroventricularly to rats. The effect of orexin-A was more potent as compared with orexin-B, suggesting the possible involvement of OX(1) receptor. The efficacy of orexin-A was almost comparable with that of angiotensin II, and the effect lasted more than 3 h. Prepro-orexin mRNA level was up-regulated when rats were deprived of water. Orexin-immunoreactive varicose axons were observed in the subfornical organ and area postrema, regions implicated in drinking behaviour. These observations suggest a physiological role for orexin as mediators that regulate drinking behaviour.
Related Concept Videos
Regulation of Food Intake
Primary Motives: Hunger and Thirst
Hunger arises when the brain detects changes in the body's nutrient levels, including glucose, lipids, amino acids, and hormones such as ghrelin and leptin. The hypothalamus plays a central role in hunger regulation. The lateral hypothalamus acts...
CNS Depressants: Alcohol and Nicotine
Neurotransmitters
Feedback Loops
Sedatives and Hypnotics Drugs: Miscellaneous Agents
Melatonin congeners like ramelteon (Rozerem) and tasimelteon (Hetlioz) selectively bind to melatonin receptors (MT1 and MT2) and thus mimic the actions of melatonin, a hormone that regulates sleep-wake cycles. Tasimelteon is primarily used for non-24-hour sleep-wake disorder, common in blind patients. They are also used to treat conditions like insomnia...
