Work

Substance P in the anterior thalamic paraventricular nucleus: promotion of ethanol drinking in response to orexin from the hypothalamus

Year: 2015

Type: article

Abstract: The paraventricular nucleus of the thalamus (PVT) appears to participate in drug addiction. Recent evidence in rats shows that ethanol drinking is increased by orexin/hypocretin (OX) afferents from the hypothalamus, acting specifically in the anterior (aPVT) rather than posterior (pPVT) PVT subregion. The present study sought to identify neuropeptides transcribed within the PVT, which themselves might contribute to ethanol drinking and possibly mediate the actions of OX. We discovered that substance P (SP) in the aPVT can stimulate intermittent-access ethanol drinking, similar to OX, and that SP receptor [neurokinin 1 receptor/tachykinin receptor 1 (NK1R)] antagonists in this subregion reduce ethanol drinking. As with OX, this effect is site specific, with SP in the pPVT or dorsal third ventricle having no effect on ethanol drinking, and it is behaviorally specific, with SP in the aPVT reducing the drinking of sucrose and stimulating it in the pPVT. A close relationship between SP and OX was demonstrated by a stimulatory effect of local OX injection on SP mRNA and peptide levels, specifically in the aPVT but not pPVT, and a stimulatory effect of OX on SP expression in isolated thalamic neurons, reflecting postsynaptic actions. A functional relationship between OX and SP in the aPVT is suggested by our additional finding that ethanol drinking induced by OX is blocked by a local NK1R antagonist administered at a sub-threshold dose. These results, suggesting that SP in the aPVT mediates the stimulatory effect of OX on ethanol drinking, identify a new role for SP in the control of this behavior.

Source: Addiction Biology

DOI: 10.1111/adb.12288

Authors: Jessica R. Barson, Kinning Poon, Hui Tin Ho, Mohammad I. Alam, Lilia Sanzalone, Sarah F. Leibowitz

Institutions: Drexel University, Rockefeller University

Language: English

Topic: Neuropeptides and Animal Physiology

Subfield: Cellular and Molecular Neuroscience

Field: Neuroscience

Domain: Life Sciences

SDG: Good health and well-being

Open Access status: green

Funders: National Institutes of Health, National Institute on Alcohol Abuse and Alcoholism, National Institute of Diabetes and Digestive and Kidney Diseases, National Center for Advancing Translational Sciences